Fix race condition in WakeLocks.

A previous fix to PowerManager.WakeLock introduced a new bug. When
a reference counted wakelock (such as SMSDispatcher) is acquired
multiple times in quick succession with a timeout, the first timeout
would remove the second callback from the handler, decrement the
reference count, but then the wakelock never gets released because
the second callback has been removed.

Bug: 4535237
Change-Id: I4f1240189bf3ed3396c86200c687282597b107d6

core/java/android/os/PowerManager.java

@@ -313,8 +313,8 @@ public class PowerManager
          */
         public void release(int flags) {
             synchronized (mToken) {
-                mHandler.removeCallbacks(mReleaser);
                 if (!mRefCounted || --mCount == 0) {
+                    mHandler.removeCallbacks(mReleaser);
                     try {
                         mService.releaseWakeLock(mToken, flags);
                     } catch (RemoteException e) {