mm-video: secure/unsecure display calls

- In secure mode, call hwcservice APIs to signal start and end
  of a secure session
- This is to synchronize secure video sessions with display sub-system

(cherry picked from commit 1de29d97e02475a7538ab7897f5e107422a0eb2e)

Conflicts:

	mm-video/vidc/vdec/Android.mk

Change-Id: I0b62481426c4269797d68b5b60a0d7fe94e507d0
(cherry picked from commit 652e360c8336e2f7d74a1eb8e439da378440bfe7)

Conflicts:
	mm-video/vidc/vdec/Android.mk