am e78edc64: am da1253b4: am 47c0c134: Fix NPE in pausePlayback

* commit 'e78edc6423fdc46dc85d79d5416505ba55be02f1':
  Fix NPE in pausePlayback
diff --git a/src/com/android/dialer/voicemail/VoicemailPlaybackPresenter.java b/src/com/android/dialer/voicemail/VoicemailPlaybackPresenter.java
index 19f7145..22a3a45 100644
--- a/src/com/android/dialer/voicemail/VoicemailPlaybackPresenter.java
+++ b/src/com/android/dialer/voicemail/VoicemailPlaybackPresenter.java
@@ -619,7 +619,9 @@
         }
         mAudioManager.abandonAudioFocus(this);
 
-        mActivity.getWindow().clearFlags(LayoutParams.FLAG_KEEP_SCREEN_ON);
+        if (mActivity != null) {
+            mActivity.getWindow().clearFlags(LayoutParams.FLAG_KEEP_SCREEN_ON);
+        }
         disableProximitySensor(true /* waitForFarState */);
     }