Active display: register/unregister recievers and listeners when enabled/disabled

Change-Id: Ic73e63da2c9634bc864ab1a1387eb9145eb0b5b0
Active display: Unify (un)registering callbacks and add proper checks.

Change-Id: Ie4c4660a54d2c60831f7a3bcc66b3a9ca1d035f2
Revert "Camera: Adds support for meta data callbacks"

This reverts commit c6ace93cf61ffd2eb36aad46d0d55573ccd7a242.
Merge commit '1a18836' into jbam10