Make sure there are bubbles before animating due to IME changes.

Also, don't crash if we try to spring the first bubble when there are no bubbles.

Fixes: 127275756
Test: atest SystemUITests
Change-Id: I6259398d894039d42f93300d0d997d14372f07b6
diff --git a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java
index 471619e..656d757 100644
--- a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java
+++ b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java
@@ -582,12 +582,9 @@
                 int displayRotation) throws RemoteException {}
 
         @Override
-        public void onImeVisibilityChanged(boolean imeVisible, int imeHeight)
-                throws RemoteException {
-            if (mStackView != null) {
-                mStackView.post(() -> {
-                    mStackView.onImeVisibilityChanged(imeVisible, imeHeight);
-                });
+        public void onImeVisibilityChanged(boolean imeVisible, int imeHeight) {
+            if (mStackView != null && mStackView.getBubbleCount() > 0) {
+                mStackView.post(() -> mStackView.onImeVisibilityChanged(imeVisible, imeHeight));
             }
         }