Support querying active record sources

Add support for querying whether there is currently a recording
 underway from the specified audio source.

Bug 7314859

Change-Id: I986b231a10ffd368b08ec2f9c7f348d28eaeb892
diff --git a/include/media/IAudioPolicyService.h b/include/media/IAudioPolicyService.h
index fb556af..cc2e069 100644
--- a/include/media/IAudioPolicyService.h
+++ b/include/media/IAudioPolicyService.h
@@ -88,6 +88,7 @@
     virtual status_t unregisterEffect(int id) = 0;
     virtual status_t setEffectEnabled(int id, bool enabled) = 0;
     virtual bool     isStreamActive(audio_stream_type_t stream, uint32_t inPastMs = 0) const = 0;
+    virtual bool     isSourceActive(audio_source_t source) const = 0;
     virtual status_t queryDefaultPreProcessing(int audioSession,
                                               effect_descriptor_t *descriptors,
                                               uint32_t *count) = 0;