Cherry-pick: Add callback-based support for HW Activity Recognition.

Add a callback-based mechanism for GmsCore to connect to Hardware Activity
Recognition. This allows GmsCore to stop polling to identify if the Android
platform supports the functionality or not.

Bug: 17112184
Change-Id: I8f9459cbd15eecd70f6919c6551e6f7a663c732f
diff --git a/Android.mk b/Android.mk
index 2a87fd2..6f5f8f9 100644
--- a/Android.mk
+++ b/Android.mk
@@ -173,6 +173,7 @@
 	core/java/android/hardware/input/IInputManager.aidl \
 	core/java/android/hardware/input/IInputDevicesChangedListener.aidl \
 	core/java/android/hardware/location/IActivityRecognitionHardware.aidl \
+	core/java/android/hardware/location/IActivityRecognitionHardwareClient.aidl \
 	core/java/android/hardware/location/IActivityRecognitionHardwareSink.aidl \
 	core/java/android/hardware/location/IActivityRecognitionHardwareWatcher.aidl \
 	core/java/android/hardware/location/IFusedLocationHardware.aidl \