1/N Add Controllers for most KeyguardBouncer related views.

This adds Controllers to most of the KeyguardBouncer related views,
though it does not move much (or any) functionality into them.

This is the first step of a few to get View Injection out of the
KeyguardMessageArea. The CL was growing large, and I wanted to find
a good check-in point before continuing.

I also added a "ViewController" utility class in this CL that
simplifies some of the repetetive work I've been finding myself
writing when implementing other Controllers. It is intentionally
left simple, existing only to hook into view lifecycle events.

More work to follow.

Bug: 166448040
Test: manual && atest SystemUITests
Change-Id: Ie59f62e97d979fb753e4a103d37ceca02e327238