Skip caching if any layer has protected contents

When a protected layer exists, it causes rendering issues with caching. They can be safely excluded as caching is usually not really useful with protected layers.
Bug: 191420183
Test: play a secure video with ExoPlayer, e.g., Secure->Clear->Secure
(cenc), check if flicking occurs

Change-Id: I31a01ee7da0e48f699f0fff7d2af410b648841e2
2 files changed