Remove mVideoPaused from VideoPreference

- We destoryed the MediaPlayer when VideoPreference is onPause().
When VideoPreference is onResumed, MediaPlayer always start from
pause state, we don't need a data save/restore current video state.

Bug: 143270527
Test: robolectric, manual
Change-Id: I544e933e4237f6d92aeff8a7eb04b52e89d74a4a

tests/robotests/src/com/android/settings/widget/VideoPreferenceControllerTest.java

@@ -21,7 +21,6 @@ import static com.android.settings.core.BasePreferenceController.UNSUPPORTED_ON_
 
 import static com.google.common.truth.Truth.assertThat;
 
-import static org.mockito.Mockito.anyBoolean;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
@@ -92,6 +91,6 @@ public class VideoPreferenceControllerTest {
 
         mController.onResume();
 
-        verify(mPreference).onViewVisible(anyBoolean());
+        verify(mPreference).onViewVisible();
     }
 }