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/app/utilities/vm-migration/VmMigrationComponent.html b/src/app/utilities/vm-migration/VmMigrationComponent.html
index fa1cd14..ee2078f 100644
--- a/src/app/utilities/vm-migration/VmMigrationComponent.html
+++ b/src/app/utilities/vm-migration/VmMigrationComponent.html
@@ -23,7 +23,7 @@
 </div>
 <form [formGroup]="migrationForm" (ngSubmit)="triggerMigration()" autocomplete="off">
     <div class="modal-body">
-        <div class="form-group row">
+        <div class="form-group row mb-3">
             <label class="col-sm-12 col-form-label mandatory-label"
                 [ngClass]="{'text-danger': migrationForm.invalid === true && submitted === true}">
                 {{'MANDATORYCHECK' | translate}}
@@ -39,7 +39,7 @@
                 <small class="form-text text-muted" *ngIf="selectedvnfId !== ''">vnfd-id : {{ selectedvnfId }}</small>
             </div>
         </div>
-        <div class="form-group row">
+        <div class="form-group row mb-3">
             <div class="col-sm-6">
                 <label for="vduid"> {{'VDUID' | translate}}</label>
             </div>
@@ -50,7 +50,7 @@
                 </ng-select>
             </div>
         </div>
-        <div class="form-group row">
+        <div class="form-group row mb-3">
             <div class="col-sm-6">
                 <label for="countIndex"> {{'COUNTINDEX' | translate}}</label>
             </div>
@@ -62,7 +62,7 @@
                 </ng-select>
             </div>
         </div>
-        <div class="form-group row">
+        <div class="form-group row mb-3">
             <div class="col-sm-6">
                 <label for="migrateToHost"> {{'MIGRATETOHOST' | translate}}</label>
             </div>
diff --git a/src/app/utilities/vm-migration/VmMigrationComponent.ts b/src/app/utilities/vm-migration/VmMigrationComponent.ts
index b629497..27f60e1 100644
--- a/src/app/utilities/vm-migration/VmMigrationComponent.ts
+++ b/src/app/utilities/vm-migration/VmMigrationComponent.ts
@@ -18,7 +18,6 @@
 /**
  * @file Vm Migration Component
  */
-import { isNullOrUndefined } from 'util';
 import { HttpHeaders } from '@angular/common/http';
 import { Component, Injector, Input, OnInit } from '@angular/core';
 import { AbstractControl, FormBuilder, FormGroup, Validators } from '@angular/forms';
@@ -28,7 +27,7 @@
 import { environment } from 'environment';
 import { VMMIGRATION } from 'NSInstanceModel';
 import { RestService } from 'RestService';
-import { SharedService } from 'SharedService';
+import { SharedService, isNullOrUndefined } from 'SharedService';
 import { InstanceData, VDUR, VNFInstanceDetails } from 'VNFInstanceModel';
 
 /**