Launcher3: Fix monkey crash in RecentsLaunchAnimator

It will appear a null object crash in quickstep launch
when monkey test. Althoough the 'View v' is declared as NonNull,
but there is a probability that it will return a null object
after the 'isTaskViewVisible' judgement in 'findTaskViewToLaunch',
Make a judgement before use to avoid crash.

Change-Id: I4606853325641feaf26a79791cce2514cee80d4c
Signed-off-by: Anle Pan <[email protected]>
Signed-off-by: Pranav Vashi <[email protected]>

quickstep/src/com/android/quickstep/TaskViewUtils.java

@@ -647,6 +647,7 @@ public static void composeRecentsLaunchAnimator(@NonNull AnimatorSet anim, @NonN
         boolean skipLauncherChanges = !launcherClosing;
 
         TaskView taskView = findTaskViewToLaunch(recentsView, v, appTargets);
+        if (taskView == null) return;
         PendingAnimation pa = new PendingAnimation(RECENTS_LAUNCH_DURATION);
         createRecentsWindowAnimator(recentsView, taskView, skipLauncherChanges, appTargets,
                 wallpaperTargets, nonAppTargets, depthController, pa);