AudioService: fix regression on hearing aid profile

Fix regression introduced by Commit 3fe5af48 where the
hearing aid profile is not stored in BtHelper.

Bug: 211530990
Test: make
Merged-In: Ie3f8757f5fec78df2da028791e9ba2ebb5833675
Change-Id: Ie3f8757f5fec78df2da028791e9ba2ebb5833675

services/core/java/com/android/server/audio/BtHelper.java

@@ -482,6 +482,8 @@ public class BtHelper {
         }
         if (profile == BluetoothProfile.A2DP) {
             mA2dp = (BluetoothA2dp) proxy;
+        } else if (profile == BluetoothProfile.HEARING_AID) {
+            mHearingAid = (BluetoothHearingAid) proxy;
         } else if (profile == BluetoothProfile.LE_AUDIO) {
             mLeAudio = (BluetoothLeAudio) proxy;
         }