Separate sniffing from session initialization

This avoid lengthy/duplicate sniffing for drm plugins when a decrypt session is opened

o The change is backward compatibile in that no update is required
  for existing drm plug-ins if they do not plan to provide separate
  sniffer/extractor

related-to-bug: 5725548

Change-Id: I7fc4caf82d77472da4e2bc7b5d31060fb54fd84c
27 files changed
tree: 382639f8cc7f1a3677589d7dfca37b667ea4261c
  1. camera/
  2. cmds/
  3. drm/
  4. include/
  5. media/
  6. services/