Create SoundTriggerSession and associated collection within common

This patch creates a SoundTriggerSession and associated collection within
common policy pillar elements.
It moves the code from managerdefault and creates helpers function within
the collection.

Change-Id: I83ea230573c05e8ab99f4489c20059ed27678221
Signed-off-by: François Gaffie <francois.gaffie@intel.com>
diff --git a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
index 01400ec..5341559 100644
--- a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
+++ b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
@@ -2458,21 +2458,7 @@
     *ioHandle = (audio_io_handle_t)mpClientInterface->newAudioUniqueId();
     *device = getDeviceAndMixForInputSource(AUDIO_SOURCE_HOTWORD);
 
-    mSoundTriggerSessions.add(*session, *ioHandle);
-
-    return NO_ERROR;
-}
-
-status_t AudioPolicyManager::releaseSoundTriggerSession(audio_session_t session)
-{
-    ssize_t index = mSoundTriggerSessions.indexOfKey(session);
-    if (index < 0) {
-        ALOGW("acquireSoundTriggerSession() session %d not registered", session);
-        return BAD_VALUE;
-    }
-
-    mSoundTriggerSessions.removeItem(session);
-    return NO_ERROR;
+    return mSoundTriggerSessions.acquireSession(*session, *ioHandle);
 }
 
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