Let getOriginalMimeType() take a fd passed from drm java applications

This patch enables the drm framework to avoid opening files directly.
As a result, the drm framework no longer needs the sdcard read permision.

o related-to-bug: 6426185

Change-Id: Ib176c35ef4b1a1a405e8e954f19a7985266f2510
19 files changed