Merge "Fix activity leak in QuickstepLauncher" into main
diff --git a/quickstep/src/com/android/launcher3/uioverrides/QuickstepLauncher.java b/quickstep/src/com/android/launcher3/uioverrides/QuickstepLauncher.java
index 165ed80..5b0c8c3 100644
--- a/quickstep/src/com/android/launcher3/uioverrides/QuickstepLauncher.java
+++ b/quickstep/src/com/android/launcher3/uioverrides/QuickstepLauncher.java
@@ -480,7 +480,11 @@
 
     @Override
     public void onDestroy() {
-        mAppTransitionManager.onActivityDestroyed();
+        if (mAppTransitionManager != null) {
+            mAppTransitionManager.onActivityDestroyed();
+        }
+        mAppTransitionManager = null;
+
         if (mUnfoldTransitionProgressProvider != null) {
             SystemUiProxy.INSTANCE.get(this).setUnfoldAnimationListener(null);
             mUnfoldTransitionProgressProvider.destroy();