Update of DRM Framework.

-Access permission handling
  Introduce an internal function which allows the desired process to
  access decryption flow. This new function is just for reference and
  each OEM manufacturer should implement/replace with their solutions.
-New API, getMetadata()
  This API is for retrieving media metadata from container-based DRM,
  such as OMA forward-lock content. This API asks DRM agent to retrieve
  media metadata hiddein inside of DRM special container.
-New API, acquireRights()
  This API wraps acquireDrmInfo() and processDrmInfo().
  If DRM agent has valid implementation of both APIs,
  Application can acquire DrmRights only by calling this API.
-Bug fix in event loop of OnInfoListener.
  Separate OnInfo event loop from mail thread loop so as to avoid
  the issue that message is not dispatched when mail thread is busy.

Changes are made by SEMC and Sony.

Change-Id: I04ee3e0988152a71e221f2256d83253749a29da0