Active Display: send unlock broadcast

This will unregister the receiver and fix the memory leak.

Change-Id: Ib99c27c6ad57eaf14d7e9f1adf2a651133ed2503
Signed-off-by: Dirk Rettschlag <dirk.rettschlag@gmail.com>
Merge branch 'jb-mr2' of https://github.com/AOKP/frameworks_base into jb-mr2