[Catalyst] Location screen migration

- Add a flag for the migration
- Add the skeleton of the screen

Test: atest LocationScreenTest
Bug: 368360458
Flag: com.android.settings.flags.catalyst_location_settings
Change-Id: Id8b7d748210d1cacf99e3d61236706029b862289

aconfig/catalyst/location.aconfig

@@ -0,0 +1,9 @@
+package: "com.android.settings.flags"
+container: "system"
+
+flag {
+  name: "catalyst_location_settings"
+  namespace: "android_settings"
+  description: "Flag for Location"
+  bug: "323791114"
+}