Angular upgrade

	- Upgraded Angular from 14 to 15 version.

Change-Id: I2339a04020153cbc9ed7a14bfe8e0aa265e507da
Signed-off-by: SANDHYA.JS <sandhya.j@tataelxsi.co.in>
diff --git a/src/services/AcessGuardService.ts b/src/services/AcessGuardService.ts
index 1ee7f64..ec77d04 100644
--- a/src/services/AcessGuardService.ts
+++ b/src/services/AcessGuardService.ts
@@ -28,6 +28,7 @@
  * @Injectable takes a metadata object that tells Angular how to compile and run module code
  */
 @Injectable()
+// eslint-disable-next-line deprecation/deprecation
 export class AcessGuardService implements CanLoad {
     /**
      * check if module can be loaded
diff --git a/src/services/AuthGuardService.ts b/src/services/AuthGuardService.ts
index 512705f..3e0ef8f 100644
--- a/src/services/AuthGuardService.ts
+++ b/src/services/AuthGuardService.ts
@@ -30,6 +30,7 @@
  * @Injectable takes a metadata object that tells Angular how to compile and run module code
  */
 @Injectable()
+// eslint-disable-next-line deprecation/deprecation
 export class AuthGuardService implements CanActivate {
     /** Holds teh instance of AuthService class of type AuthService @private */
     private router: Router;
diff --git a/src/services/AuthenticationService.ts b/src/services/AuthenticationService.ts
index d01eec6..904c1cf 100644
--- a/src/services/AuthenticationService.ts
+++ b/src/services/AuthenticationService.ts
@@ -18,7 +18,6 @@
 /**
  * @file Auth service
  */
-import { isNullOrUndefined } from 'util';
 import { HttpHeaders } from '@angular/common/http';
 import { Injectable, Injector } from '@angular/core';
 import { Router } from '@angular/router';
@@ -28,6 +27,7 @@
 import { environment } from 'environment';
 import { BehaviorSubject, Observable } from 'rxjs';
 import { map } from 'rxjs/operators';
+import { isNullOrUndefined } from 'SharedService';
 import { SharedService } from 'SharedService';
 import { ProjectModel } from '../models/VNFDModel';
 import { RestService } from './RestService';
diff --git a/src/services/RestService.ts b/src/services/RestService.ts
index d3d9ea0..5f47fb1 100644
--- a/src/services/RestService.ts
+++ b/src/services/RestService.ts
@@ -20,7 +20,6 @@
  * @file Provider for REST Service
  */
 
-import { isNullOrUndefined } from 'util';
 import { HttpClient, HttpHeaders } from '@angular/common/http';
 import { Injectable } from '@angular/core';
 import { NgbModal } from '@ng-bootstrap/ng-bootstrap';
@@ -41,6 +40,9 @@
     private http: HttpClient;
     /** API URL. Disabled tslint since server doesn't support https protocol */
     private apiURL: string = '';
+    /** Method to handle null or undefined @private */
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    private isNullOrUndefined = (data: any): boolean => data === null || data === undefined;
     /** Notifier service to popup notification @private */
     private notifierService: NotifierService;
     /** Instance for active modal service @public */
@@ -62,7 +64,7 @@
 
     public getResource(apiURL: string, httpHeaders?: { headers: HttpHeaders }): Observable<{}> {
         const getRequest: APIURLHEADER = this.getHttpoptions(apiURL);
-        if (!isNullOrUndefined(httpHeaders)) {
+        if (!this.isNullOrUndefined(httpHeaders)) {
             return this.http.get(apiURL, httpHeaders);
         } else {
             return this.http.get(getRequest.url, getRequest.httpOptions);
@@ -77,7 +79,7 @@
 
     public postResource(apiURLHeader: { url: string, httpOptions?: { headers: HttpHeaders } }, payload: {}): Observable<{}> {
         const getRequest: APIURLHEADER = this.getHttpoptions(apiURLHeader.url);
-        if (!isNullOrUndefined(apiURLHeader.httpOptions)) {
+        if (!this.isNullOrUndefined(apiURLHeader.httpOptions)) {
             return this.http.post(apiURLHeader.url, payload, apiURLHeader.httpOptions);
         } else {
             return this.http.post(getRequest.url, payload, getRequest.httpOptions);
@@ -92,7 +94,7 @@
 
     public patchResource(apiURLHeader: { url: string, httpOptions?: { headers: HttpHeaders } }, payload: {}): Observable<object> {
         const getRequest: APIURLHEADER = this.getHttpoptions(apiURLHeader.url);
-        if (!isNullOrUndefined(apiURLHeader.httpOptions)) {
+        if (!this.isNullOrUndefined(apiURLHeader.httpOptions)) {
             return this.http.patch(apiURLHeader.url, payload, apiURLHeader.httpOptions);
         } else {
             return this.http.patch(getRequest.url, payload, getRequest.httpOptions);
@@ -107,7 +109,7 @@
 
     public putResource(apiURLHeader: { url: string, httpOptions?: { headers: HttpHeaders } }, payload: {}): Observable<object> {
         const getRequest: APIURLHEADER = this.getHttpoptions(apiURLHeader.url);
-        if (!isNullOrUndefined(apiURLHeader.httpOptions)) {
+        if (!this.isNullOrUndefined(apiURLHeader.httpOptions)) {
             return this.http.put(apiURLHeader.url, payload, apiURLHeader.httpOptions);
         } else {
             return this.http.put(getRequest.url, payload, getRequest.httpOptions);
@@ -121,7 +123,7 @@
 
     public deleteResource(apiURL: string, httpHeaders?: { headers: HttpHeaders }): Observable<object> {
         const getRequest: APIURLHEADER = this.getHttpoptions(apiURL);
-        if (!isNullOrUndefined(httpHeaders)) {
+        if (!this.isNullOrUndefined(httpHeaders)) {
             return this.http.delete(apiURL, httpHeaders);
         } else {
             return this.http.delete(getRequest.url, getRequest.httpOptions);
diff --git a/src/services/SharedService.ts b/src/services/SharedService.ts
index 8fb51bf..00f0a63 100644
--- a/src/services/SharedService.ts
+++ b/src/services/SharedService.ts
@@ -18,7 +18,6 @@
 /**
  * @file Provider for Shared Service
  */
-import { isNullOrUndefined } from 'util';
 import { HttpErrorResponse, HttpHeaders } from '@angular/common/http';
 import { EventEmitter, Injectable, Output } from '@angular/core';
 import { FormArray, FormGroup } from '@angular/forms';
@@ -514,3 +513,8 @@
         };
     }
 }
+
+/** Method to handle null or undefined @public */
+// eslint-disable-next-line @typescript-eslint/no-explicit-any, @typescript-eslint/explicit-module-boundary-types
+export const isNullOrUndefined = (data: any): boolean => data === null || data === undefined;
+