HDMI: Guard mEarcLocalDevice.mEarcStatus with mLock

This fixes an error prone reported in udc-tv-dev cherry-pick.

Test: atest HdmiCecAtomLoggingTest
Bug: 287180347
Change-Id: I4a6b6e62e01d8ee2be17c5620cf926e9c9dd610e

services/core/java/com/android/server/hdmi/HdmiControlService.java

@@ -4689,7 +4689,9 @@ public class HdmiControlService extends SystemService {
     private int getEarcStatus() {
         assertRunOnServiceThread();
         if (mEarcLocalDevice != null) {
-            return mEarcLocalDevice.mEarcStatus;
+            synchronized (mLock) {
+                return mEarcLocalDevice.mEarcStatus;
+            }
         }
         return HDMI_EARC_STATUS_UNKNOWN;
     }