Revert "Revert "ANDROID: Communicates LMK events to userland where they can be logged""

This reverts commit 9fd99422.
The feature caused crash so we may wait until it's stable.

Change-Id: Ibb5d9326dc9fde344dd76308878d7f106d21035a
Signed-off-by: Zhenhua Huang <zhenhuah@codeaurora.org>