Don't look through the buffer cache in protected contexts

Test: manual - blurred protected content in Netflix apk

Without this change getOrCreateBackendTexture can return an
un-Protected backend texture when a Protected one is required.
This causes the Protected content draw to be dropped.

Bug: 242266174
Change-Id: I9d7bab890ae8d88656e77dede962b40e926580c8
1 file changed