Made audiohooks, framehooks, and monitor prevent local channel optimization.

Audiohooks, framehooks, and monitor represent state on a local channel
that will go away if it is optimized out.

(closes issue ASTERISK-21954)
Reported by: rmudgett

Review: https://reviewboard.asterisk.org/r/2685/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@394791 65c4cc65-6c06-0410-ace0-fbb531ad65f3