Don't enable a11y service if scary dialog obscured

We were only checking if the OK button itself was obscured.
Changing to check if any part of the window is obscured.

Bug: 31855267
Test: Created a sample a11y service that displays a UI to cover
part of the window, but not the OK button. It was possible to
enable an a11y service before this change, but now it displays
a warning toast.

Change-Id: I21974535aba734da6ea9d7accf67fb9237fd16fc
diff --git a/src/com/android/settings/accessibility/AccessibilityServiceWarning.java b/src/com/android/settings/accessibility/AccessibilityServiceWarning.java
index 71cafba..9f89bc1 100644
--- a/src/com/android/settings/accessibility/AccessibilityServiceWarning.java
+++ b/src/com/android/settings/accessibility/AccessibilityServiceWarning.java
@@ -53,7 +53,7 @@
 
         final View.OnTouchListener filterTouchListener = (View v, MotionEvent event) -> {
             // Filter obscured touches by consuming them.
-            if ((event.getFlags() & MotionEvent.FLAG_WINDOW_IS_OBSCURED) != 0) {
+            if ((event.getFlags() & MotionEvent.FLAG_WINDOW_IS_PARTIALLY_OBSCURED) != 0) {
                 if (event.getAction() == MotionEvent.ACTION_UP) {
                     Toast.makeText(v.getContext(), R.string.touch_filtered_warning,
                             Toast.LENGTH_SHORT).show();