Don't display the option menu when all option menu items invisible

When all option menu items are invisible, return false in
onPrepareOptionsMenu(), don't display the blank option menu.

Bug: 37526369
Test: manual
Merged-In: I17de5523e9fa5ae47daee79a9f374809275c386d
Change-Id: I17de5523e9fa5ae47daee79a9f374809275c386d
diff --git a/src/com/android/stk/StkMenuActivity.java b/src/com/android/stk/StkMenuActivity.java
index 1e5634e..04e5ed0 100755
--- a/src/com/android/stk/StkMenuActivity.java
+++ b/src/com/android/stk/StkMenuActivity.java
@@ -293,7 +293,7 @@
     public void onDestroy() {
         getListView().setOnCreateContextMenuListener(null);
         super.onDestroy();
-        CatLog.d(LOG_TAG, "onDestroy" + "," + mState);
+        CatLog.d(LOG_TAG, "onDestroy" + ", " + mState);
         if (appService == null || !SubscriptionManager.isValidSlotIndex(mSlotId)) {
             return;
         }
@@ -330,7 +330,7 @@
 
         menu.findItem(StkApp.MENU_ID_END_SESSION).setVisible(mainVisible);
 
-        return true;
+        return mainVisible;
     }
 
     @Override