MtpClient: remove finalize override to avoid multiple calls to unregisterReceiver

BUG: 3497801

Change-Id: I4ed0166efcc509a18361287c5816bc4844089025
Signed-off-by: Mike Lockwood <lockwood@android.com>

media/java/android/mtp/MtpClient.java

@@ -163,15 +163,6 @@ public class MtpClient {
         mContext.unregisterReceiver(mUsbReceiver);
     }
 
-    @Override
-    protected void finalize() throws Throwable {
-        try {
-            close();
-        } finally {
-            super.finalize();
-        }
-    }
-
     /**
      * Registers a {@link android.mtp.MtpClient.Listener} interface to receive
      * notifications when MTP or PTP devices are added or removed.