Move code from CarSystemBars to controller class

In this cl, the logic from CarSystemBars class is moving to
the CarSystemBarController class.
In follow up cls, CarSystemBarController will become an interface and
the implementation will be decided based on the configuration.

Bug: 360420094
Test: atest CarSystemUITests
Flag: EXEMPT internal cleanup
Change-Id: Ie49719290501ebc5dc4034ef5f0bdadfef1b6122
6 files changed