DSPManager: update action bar / indicator

This commit updates the look of the ActionBar to be more
consistent with other CM apps (mainly Apollo.) Switches from tabs
to PagerTabStrip to be more consistent as well. Create theme
resources so more items can be added at a later time to complete
the look.

Change-Id: I0df6af2941e3d3f370144f8ed469880b7e15ff61