fix(android): drop geolocator for a native LocationManager channel

Removes the geolocator dependency, which transitively embedded
com.google.android.gms.* (play-services-location) — proprietary classes
that F-Droid's scanner rejects. The optional coarse-location button now
talks to Android's own LocationManager over a small platform channel
(org.comunes.tane/coarse_location): permission prompt, single coarse fix
with a 12s timeout, last-known fallback, null on any failure. Behavior
is unchanged and the CoarseLocationProvider interface is preserved, so
the UI, i18n and widget tests need no changes.

Also sets dependenciesInfo.includeInApk/Bundle = false so the AGP
dependency-metadata block (also flagged by F-Droid) is not embedded.
Neither change affects the Google Play build.

apps/app_seeds/lib/bootstrap.dart

@@ -86,7 +86,7 @@ class _BootstrapState extends State<Bootstrap> {
           getIt.isRegistered<SocialService>() ? getIt<SocialService>() : null,
       socialSettings: getIt<SocialSettings>(),
       connection: connection,
-      location: const GeolocatorCoarseLocation(),
+      location: const NativeCoarseLocation(),
       outbox: getIt<OfferOutbox>(),
       messageStore: getIt<MessageStore>(),
       profileStore: getIt<ProfileStore>(),