Transparent activity orientation problem when previous landsacpe fullscreen...

Transparent activity orientation problem when previous landsacpe fullscreen activity not yet destroyed.

After terminating landsacpe fullscreen activity,
when user launch transparent activity via portrait home app, transparent activity is shown as landscape mode.

At this time AppWindowToken of previous acitivity has not been deleted, because Activity.onDestory() has not been returned yet.
In this case, getOrientationFromAppTokensLocked() returned ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE.

Ignore hidden application is terminated on the top.
See also http://code.google.com/p/android/issues/detail?id=28927

Change-Id: I51239431120ec6ba8f8ff76871efb2347b9810ca