Audio : Fix minor comments in r_submix module

Add missing check for StandbyTransition variable
Add missing & in const arguments

Bug: 286914845
Test: atest VtsHalAudioCoreTargetTest
Change-Id: Id7a30e0697da80a272768bbf2aa8e3ed748e93f4
diff --git a/audio/aidl/default/r_submix/SubmixRoute.h b/audio/aidl/default/r_submix/SubmixRoute.h
index 5f7ea75..1a98df2 100644
--- a/audio/aidl/default/r_submix/SubmixRoute.h
+++ b/audio/aidl/default/r_submix/SubmixRoute.h
@@ -93,9 +93,9 @@
         return mSource;
     }
 
-    bool isStreamConfigValid(bool isInput, const AudioConfig streamConfig);
+    bool isStreamConfigValid(bool isInput, const AudioConfig& streamConfig);
     void closeStream(bool isInput);
-    ::android::status_t createPipe(const AudioConfig streamConfig);
+    ::android::status_t createPipe(const AudioConfig& streamConfig);
     void exitStandby(bool isInput);
     bool hasAtleastOneStreamOpen();
     int notifyReadError();
@@ -107,7 +107,7 @@
     long updateReadCounterFrames(size_t frameCount);
 
   private:
-    bool isStreamConfigCompatible(const AudioConfig streamConfig);
+    bool isStreamConfigCompatible(const AudioConfig& streamConfig);
 
     std::mutex mLock;