Remove callback to invalidate menu if necessary

Otherwise it can leak strong reference to the entire activity
in the queue that stores all posted callbacks.

Test: inspect the queue of actions in debugger
Bug: 31764132
Change-Id: If82b48928c9ae5231e613a011916af1df41ae741
diff --git a/v7/appcompat/src/android/support/v7/app/AppCompatDelegateImplV9.java b/v7/appcompat/src/android/support/v7/app/AppCompatDelegateImplV9.java
index 4e25f71..a203252 100644
--- a/v7/appcompat/src/android/support/v7/app/AppCompatDelegateImplV9.java
+++ b/v7/appcompat/src/android/support/v7/app/AppCompatDelegateImplV9.java
@@ -304,6 +304,10 @@
 
     @Override
     public void onDestroy() {
+        if (mInvalidatePanelMenuPosted) {
+            mWindow.getDecorView().removeCallbacks(mInvalidatePanelMenuRunnable);
+        }
+
         super.onDestroy();
 
         if (mActionBar != null) {