Add status/navigation bar existing check before create input consumer.

We create input consumer to show navigation bar after developer setting the
related immersive flags. The InputConsumer is using status bar to implement the
feature. But the some devices does not have status bar and navigation bar.
Which will cause that most video players can not show UI controller after
entering fullscreen mode because InputConsumer consumes them always.

Fix this by checking whether the status and navigation bar exists before
creating the InputConsumer.

Test: Open Youtube Gaming and maximize it on a device without status/navigation
bar. Play any video and fullscreen it. Now click in the app can show the
UI control buttons.

Change-Id: Ibebf1d9acced55b6170077e903aaad87fa84bb2d