Abort dispatching animation callbacks if the root view is gone

This CL prevents possible NullPointerExceptions.

Bug: 118118435
Bug: 149479853
Test: atest AnimatedVectorDrawableParameterizedTest
Change-Id: I966a15c0886b80317a34541fb315b2886981af16

core/java/android/view/InsetsController.java

@@ -39,7 +39,6 @@ import android.util.Log;
 import android.util.Pair;
 import android.util.Property;
 import android.util.SparseArray;
-import android.view.InputDevice.MotionRange;
 import android.view.InsetsSourceConsumer.ShowResult;
 import android.view.InsetsState.InternalInsetsType;
 import android.view.SurfaceControl.Transaction;
@@ -855,6 +854,9 @@ public class InsetsController implements WindowInsetsController, InsetsAnimation
         } else {
             hideDirectly(types);
         }
+        if (mViewRoot.mView == null) {
+            return;
+        }
         mViewRoot.mView.dispatchWindowInsetsAnimationPrepare(animation);
         mViewRoot.mView.getViewTreeObserver().addOnPreDrawListener(new OnPreDrawListener() {
             @Override