Add the FLAG_IMMUTABLE flag for creating a PendingIntent

- Android S+ to specify explicitly either FLAG_MUTABLE or FLAG_IMMUTABLE
  when creating a PendingIntent.

Fixes: 170162598
Fixes: 170162878
Fixes: 170163592
Fixes: 170164316
Fixes: 170164458
Fixes: 170164327
Fixes: 169794524
Fixes: 170165106
Test: build pass and manual test add an account
Change-Id: I0f7b117273647dbe9e146033b8995c8c6f147576

src/com/android/settings/location/LocationSlice.java

@@ -96,6 +96,6 @@ public class LocationSlice implements CustomSliceable {
     private PendingIntent getPrimaryAction() {
         final Intent intent = getIntent();
         return PendingIntent.getActivity(mContext, 0 /* requestCode */,
-                intent, 0 /* flags */);
+                intent, PendingIntent.FLAG_IMMUTABLE);
     }
 }