Add live region politeness to View, AccessibilityNodeInfo

Alters the content change API to contain a bit mask of types of
changes represented by the event. Live regions send CONTENT_CHANGED
events immediately. Removes unused APIs for EXPANDABLE/EXPANDED.

BUG: 10527284
Change-Id: I21523e85e47df23706976dc0a8bf615f83072c04
diff --git a/core/java/android/widget/CompoundButton.java b/core/java/android/widget/CompoundButton.java
index 05a8dc8..082ff3d 100644
--- a/core/java/android/widget/CompoundButton.java
+++ b/core/java/android/widget/CompoundButton.java
@@ -114,7 +114,8 @@
         if (mChecked != checked) {
             mChecked = checked;
             refreshDrawableState();
-            notifyViewAccessibilityStateChangedIfNeeded();
+            notifyViewAccessibilityStateChangedIfNeeded(
+                    AccessibilityEvent.CONTENT_CHANGE_TYPE_UNDEFINED);
 
             // Avoid infinite recursions if setChecked() is called from a listener
             if (mBroadcasting) {