Adding null check for split bounds before notifying

Bug: 160626905
Test: Manual, just a null check
Change-Id: I94e3fd1f63edae131fa1cfe56eedad8a8d19b186

packages/SystemUI/src/com/android/systemui/stackdivider/DividerView.java

@@ -675,6 +675,9 @@ public class DividerView extends FrameLayout implements OnTouchListener,
     }
 
     private void notifySplitScreenBoundsChanged() {
+        if (mSplitLayout.mPrimary == null || mSplitLayout.mSecondary == null) {
+            return;
+        }
         mOtherTaskRect.set(mSplitLayout.mSecondary);
 
         mTmpRect.set(mHandle.getLeft(), mHandle.getTop(), mHandle.getRight(), mHandle.getBottom());