This reverts commit 1b066c8d1d.
Reason for revert: <This CL isn't related to public API which triggered previous revert>
Change-Id: If1fa2a244e5f4ee7f978cda79421172da02220f1
Add sendSessionEvent to notify hal what happened on a session.
Add onSessionEvent to listen notification from hal for a session
Test: manual
Bug: 122472761
Change-Id: I98434325915e7bee57e63bdeeedba9ed5578e493