Removed improper check on mCalledExitCoordinator.

Bug 27969302

mCalledExitCoordinator can be nulled before the onResume is called,
so it cannot be used to determine whether or not the Activity is
a caller or called.

Change-Id: Ie3696ed59b89cfc8c6145d22bc230111f0813701

core/java/android/app/ActivityTransitionState.java

@@ -239,9 +239,6 @@ class ActivityTransitionState {
     public void onResume(Activity activity, boolean isTopOfTask) {
         // After orientation change, the onResume can come in before the top Activity has
         // left, so if the Activity is not top, wait a second for the top Activity to exit.
-        if (mCalledExitCoordinator == null) {
-            return; // This is the called activity
-        }
         if (isTopOfTask || mEnterTransitionCoordinator == null) {
             restoreExitedViews();
             restoreReenteringViews();