backport miisample fix (#3083)

Author: maggiehe00

integration-tests/src/test/java/oracle/weblogic/kubernetes/utils/ItMiiSampleHelper.java

@@ -315,12 +315,16 @@ public void callUpdateUseCase(String args, String errString, String testClassNam
   public void callCheckMiiSampleSource(String args,
                                               String errString) {
     final String baseImageNameKey = "BASE_IMAGE_NAME";
+    final String baseImageTagKey = "BASE_IMAGE_TAG";
     final String origImageName = envMap.get(baseImageNameKey);
+    final String origImageTag = envMap.get(baseImageTagKey);
     try {
       envMap.remove(baseImageNameKey);
+      envMap.remove(baseImageTagKey);
       execTestScriptAndAssertSuccess(domainType, args, errString);
     } finally {
       envMap.put(baseImageNameKey,origImageName);
+      envMap.put(baseImageTagKey,origImageTag);
     }
   }