display: Add HDMI support in APIs exposed by display.

- Remove hardcoded primary display from getActiveConfig() and
  getDisplayAttributes() for video decoder to query the secondary
  display resolution.
- Add permission for Video decoder UID to call these APIs.

Change-Id: I1ec1e19dda76f2e0e085c52450449bdc13a739fa
CRs-Fixed: 1100704
2 files changed