Update overflow button on theme change

Bug: 149146374
Fixes: 149176394
Test: change theme - overflow button changes with theme
Test: atest SystemUITests
Change-Id: I04d5e59f0451cac2010519477770add46aa727ee
diff --git a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleExpandedView.java b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleExpandedView.java
index 0d5261d..fe191f4 100644
--- a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleExpandedView.java
+++ b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleExpandedView.java
@@ -294,7 +294,8 @@
         ta.recycle();
 
         mPointerDrawable.setTint(bgColor);
-        if (ScreenDecorationsUtils.supportsRoundedCornersOnWindows(mContext.getResources())) {
+        if (mActivityView != null && ScreenDecorationsUtils.supportsRoundedCornersOnWindows(
+                mContext.getResources())) {
             mActivityView.setCornerRadius(cornerRadius);
         }
     }