audio policy: add binder calls for audio source control

Add binder methods to IAudioPolicyService to control activity
of external audio sources (e.g FM tuner).

Change-Id: I2008308a6a996baeae502b68a790d87281efe2ff
diff --git a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
index ba9f996..3ea6a11 100644
--- a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
+++ b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
@@ -2462,6 +2462,18 @@
     return mSoundTriggerSessions.acquireSession(*session, *ioHandle);
 }
 
+status_t AudioPolicyManager::startAudioSource(const struct audio_port_config *source,
+                                       const audio_attributes_t *attributes,
+                                       audio_io_handle_t *handle)
+{
+    return INVALID_OPERATION;
+}
+
+status_t AudioPolicyManager::stopAudioSource(audio_io_handle_t handle)
+{
+    return INVALID_OPERATION;
+}
+
 // ----------------------------------------------------------------------------
 // AudioPolicyManager
 // ----------------------------------------------------------------------------