Prevent NPE when GlobalActions items are clicked while the dialog isn't showing.

Unclear what circumstances this can happen in, perhaps a race condition for tapping items rapidly while the phone is under heavy load and running very slowly. Added warning logs in case we need to investigate further.

Test: Automated tests pass, GlobalActionsMenu still works as expected when tapping action items.

Bug: 134514187
Change-Id: I0c50ee02cc54d046a12e56f01d9c129122fbf737
diff --git a/packages/SystemUI/src/com/android/systemui/globalactions/GlobalActionsDialog.java b/packages/SystemUI/src/com/android/systemui/globalactions/GlobalActionsDialog.java
index 8826f43..df3f36e 100644
--- a/packages/SystemUI/src/com/android/systemui/globalactions/GlobalActionsDialog.java
+++ b/packages/SystemUI/src/com/android/systemui/globalactions/GlobalActionsDialog.java
@@ -1021,7 +1021,11 @@
         public boolean onLongClickItem(int position) {
             final Action action = mAdapter.getItem(position);
             if (action instanceof LongPressAction) {
-                mDialog.dismiss();
+                if (mDialog != null) {
+                    mDialog.dismiss();
+                } else {
+                    Log.w(TAG, "Action long-clicked while mDialog is null.");
+                }
                 return ((LongPressAction) action).onLongPress();
             }
             return false;
@@ -1031,9 +1035,13 @@
         public void onClickItem(int position) {
             Action item = mAdapter.getItem(position);
             if (!(item instanceof SilentModeTriStateAction)) {
-                mDialog.dismiss();
+                if (mDialog != null) {
+                    mDialog.dismiss();
+                } else {
+                    Log.w(TAG, "Action clicked while mDialog is null.");
+                }
+                item.onPress();
             }
-            item.onPress();
         }
 
         @Override