Display on-going notification for apps using alert windows.

Allows the user to associate alert windows with specific apps
and revoke the permission if they want.

Test: manual
Bug: 33256752
Change-Id: Ie28325b6bb799b3df253770ebe655f97ebbadd90
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 97fbfa5..2f4b74e 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -520,6 +520,7 @@
     <!-- TODO: temporary broadcast used by AutoFillManagerServiceImpl; will be removed -->
     <protected-broadcast android:name="com.android.internal.autofill.action.REQUEST_AUTOFILL" />
     <protected-broadcast android:name="android.app.action.APPLICATION_DELEGATION_SCOPES_CHANGED" />
+    <protected-broadcast android:name="com.android.server.wm.ACTION_REVOKE_SYSTEM_ALERT_WINDOW_PERMISSION" />
 
     <!-- ====================================================================== -->
     <!--                          RUNTIME PERMISSIONS                           -->