Move Settings/SystemUI permissions to separate files

This makes it possible to move the permission around separately
from all the other permissions. This permission file is included
automatically when the respective app is included.

Bug: 110072687
Test: make
Change-Id: I91b30561d4a4000334ffbf3b98bb632d962f4b97

packages/SystemUI/Android.bp

@@ -150,6 +150,7 @@ android_app {
         "--extra-packages",
         "com.android.keyguard",
     ],
+    required: ["privapp_whitelist_com.android.systemui"],
 
 }