Fix for a11yManagerService broadcastReceiver ANR

Offloads hard computations to background thread so broadcastReceiver can conclude before timeout

Bug: 333890389
Flag: aconfig android.view.accessibility.Flags.manager_avoid_receiver_timeout ENABLED
Test: add a long Thread.sleep() to the runnable and verify no ANR occurs
Change-Id: I64fe4e54c836a82ad028b908fae691b469a485d7
diff --git a/services/accessibility/accessibility.aconfig b/services/accessibility/accessibility.aconfig
index eb2ef29..0448f6d 100644
--- a/services/accessibility/accessibility.aconfig
+++ b/services/accessibility/accessibility.aconfig
@@ -118,6 +118,16 @@
 }
 
 flag {
+    name: "manager_avoid_receiver_timeout"
+    namespace: "accessibility"
+    description: "Avoid broadcast receiver timeout by offloading potentially slow operations to the background thread."
+    bug: "333890389"
+    metadata {
+        purpose: PURPOSE_BUGFIX
+    }
+}
+
+flag {
     name: "pinch_zoom_zero_min_span"
     namespace: "accessibility"
     description: "Whether to set min span of ScaleGestureDetector to zero."