Use enumerator for AudioFocusChange

Bug: 175064011
Test: built & atest VtsAidlHalAudioControlTest
Change-Id: Id25ece4649981fcf7fecf070697712d5041c6ea4
diff --git a/automotive/audiocontrol/aidl/android/hardware/automotive/audiocontrol/AudioFocusChange.aidl b/automotive/audiocontrol/aidl/android/hardware/automotive/audiocontrol/AudioFocusChange.aidl
index fc35fa9..98fa4e8 100644
--- a/automotive/audiocontrol/aidl/android/hardware/automotive/audiocontrol/AudioFocusChange.aidl
+++ b/automotive/audiocontrol/aidl/android/hardware/automotive/audiocontrol/AudioFocusChange.aidl
@@ -27,7 +27,7 @@
     GAIN_TRANSIENT = 2,
     GAIN_TRANSIENT_MAY_DUCK = 3,
     GAIN_TRANSIENT_EXCLUSIVE = 4,
-    LOSS = -1, // -1 * GAIN,
-    LOSS_TRANSIENT = -2, // -1 * GAIN_TRANSIENT,
-    LOSS_TRANSIENT_CAN_DUCK = -3, // -1 * GAIN_TRANSIENT_MAY_DUCK,
+    LOSS = -1 * GAIN,
+    LOSS_TRANSIENT = -1 * GAIN_TRANSIENT,
+    LOSS_TRANSIENT_CAN_DUCK = -1 * GAIN_TRANSIENT_MAY_DUCK,
 }
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