Create the stubs lib for com.android.location.provider

com.android.location.provider.stubs is the stubs library for the shared
library com.android.location.provider. The stubs library is intended to
provide the stable set of APIs to the apps implementing location
provider.

Without the stubs library, apps had to directly link to the shared
library which is built without Android SDK and exposes private APIs that
are not intended to be used by apps. This also has been causing the
lin-type check warnings when the shared lib is used by apps built with
SDK; apps built with SDK is not allowed to link to lib built without
SDK. This has been reported as warnings but will soon be errors. Now
such apps are required to link to the stubs lib, which is built with
SDK.

While building the stubs library, following APIs are made hidden because
they are exposing private APIs from the Android platform.

1) Activity* classes are removed from the API, as they are not intended
to be used by apps since O.
2) GeocodeProvider and GeofenceProvider are removed from the API.
3) LocationProvider.mLocationManager is removed as it is exposing the
private symbol ILocationProvider
4) ProviderPropertiesUnbundle.getProviderProperties are removed from the
API as it is exposing the private symbol ProviderProperties.
5) The constructor of ProviderRequestUnbundled is removed since the
class is intended to be instantiated by the service.

Bug: 71420593
Test: m -j com.android.location.provider.stubs

Change-Id: I20aba7e9ca9c3adc75db241f37a55f0d657f3ced