Feature 10908: Update charm in running VNF instance

Adding robot test Basic 25
This test instantiates NS, updates the VNFD, update the VNF instance
by upgrading charm. Then it executes the new added action on this VNF.

Change-Id: I68140f01fadf791a512870ff0f6b0babfcb67e0c
Signed-off-by: aticig <gulsum.atici@canonical.com>
diff --git a/robot-systest/lib/vnfd_lib.robot b/robot-systest/lib/vnfd_lib.robot
index f1cc95e..2d50170 100644
--- a/robot-systest/lib/vnfd_lib.robot
+++ b/robot-systest/lib/vnfd_lib.robot
@@ -71,6 +71,24 @@
     [Return]  ${id}
 
 
+Update VNFD
+    [Documentation]   Onboards ("Updates") a NF Package into OSM.
+    ...               - Parameters:
+    ...                 - vnfd_pkg: Name (and location) of the NF Package
+    ...                 - vnfd_name: Name of the existing NF Package
+
+    [Arguments]   ${vnfd_pkg}   ${vnfd_name}
+
+    # Proceedes with the onboarding with the appropriate arguments
+    ${rc}   ${stdout}=   Run and Return RC and Output   osm vnfpkg-update --content ${vnfd_pkg} ${vnfd_name}
+    log   ${stdout}
+    Should Be Equal As Integers   ${rc}   ${success_return_code}
+    ${lines}=  Get Line Count  ${stdout}
+    ${last}=  Evaluate  ${lines} - 1
+    ${id}=  Get Line  ${stdout}  ${last}
+    [Return]  ${id}
+
+
 Create VNFD Overriding Fields
     [Documentation]   Onboards ("creates") a NF Package into OSM.
     ...               - Parameters: