Add a flag to disable HardwareActivityRecognitionProxy

This change disables the `HardwareActivityRecognitionProxy` and its usage within `LocationManagerService`. This proxy was responsible for binding GmsCore to the `ActivityRecognitionHardware`.

This feature has been deprecated for years.

Bug: 417261071
Bug: 441145460
Test: LocationProviderManagerTest
Flag: android.location.flags.disable_hardware_ar
Change-Id: If92a9bdb162bb515716638a4bcc2ad07587ee524