RenderEngine: don't blur when using protected content

Work around a bug by skipping blur when using protected content.

Bug: 244398863
Bug: 270314344
Bug: 205516620
Bug: 242266174
Bug: 213116783
Test: manual (ExoPlayer)
Change-Id: Ifcacbd4c44aee1a504a7c46f3fece51004ed7f37
(cherry picked from commit 4623eeb2)
Merged-In: Ifcacbd4c44aee1a504a7c46f3fece51004ed7f37