audiopolicy: add Volume Group introspection APIs

Change-Id: Ib02900bde69ee24685d9d374c0e5f73d33fa59e7
Signed-off-by: François Gaffie <francois.gaffie@renault.com>

Test: make
Bug: 124767636
diff --git a/services/audiopolicy/AudioPolicyInterface.h b/services/audiopolicy/AudioPolicyInterface.h
index bb5441d..9b00a4d 100644
--- a/services/audiopolicy/AudioPolicyInterface.h
+++ b/services/audiopolicy/AudioPolicyInterface.h
@@ -244,7 +244,13 @@
 
     virtual status_t listAudioProductStrategies(AudioProductStrategyVector &strategies) = 0;
 
-    virtual product_strategy_t getProductStrategyFromAudioAttributes(const AudioAttributes &aa) = 0;
+    virtual status_t getProductStrategyFromAudioAttributes(const AudioAttributes &aa,
+                                                           product_strategy_t &productStrategy) = 0;
+
+    virtual status_t listAudioVolumeGroups(AudioVolumeGroupVector &groups) = 0;
+
+    virtual status_t getVolumeGroupFromAudioAttributes(const AudioAttributes &aa,
+                                                       volume_group_t &volumeGroup) = 0;
 };