Revise Accessibility button chooser intent/permissions

1) Switch AccessibilityButtonChooserActivity to non-exported
2) Update AccessibilityButtonChooserActivity's intent action to
   be CTS-compliant
3) Switches to correct permission to validate a click of the
   accessibility button originated from the status bar service

Bug: 36866328
Bug: 36976440
Test: Manual / Created app to validate launch protection
Change-Id: Ifcd5e8dbbe683dc99bb900a5870a9ba374fbd5d4
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 7922250..c15fbfd 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -3356,6 +3356,7 @@
             </intent-filter>
         </activity>
         <activity android:name="com.android.internal.app.AccessibilityButtonChooserActivity"
+                  android:exported="false"
                   android:theme="@style/Theme.DeviceDefault.Resolver"
                   android:finishOnCloseSystemDialogs="true"
                   android:excludeFromRecents="true"
@@ -3365,7 +3366,7 @@
                   android:process=":ui"
                   android:visibleToInstantApps="true">
             <intent-filter>
-                <action android:name="android.intent.action.CHOOSE_ACCESSIBILITY_BUTTON" />
+                <action android:name="com.android.internal.intent.action.CHOOSE_ACCESSIBILITY_BUTTON" />
                 <category android:name="android.intent.category.DEFAULT" />
             </intent-filter>
         </activity>