Allow progress bar dimensions to be configured.

Added a new dimension for the bottom margin after the notification
content if there is a progress bar. This value is needed to create a
larger space for the progress bar. If it is adjusted to be larger, than
the progress bar will appear to be further away from the notification
content.

Also add dimensions for the progress bar size. This value needs to also
override the max and min heights otherwise the max/min heights would
differ from the layout_height.

Test: booted on phone and Android Auto headunit
Bug: 33210494
Change-Id: I20011b3f79a0d3f81c6317e715d8d2310c5cd87b