[Media Recs] Hide the title / subtitle views if none of the albums have

titles / subtitles so that the album art is centered better.

This required setting ConstraintSet values programmatically, which
re-surfaces the quirk we noticed earlier where if we set any
ConstraintSet values programmatically, then all the values in the layout
XML are erased. So, this CL also moves all constraints out of the layout
XML and into the ConstraintSet XML instead.

Fixes: 229377153
Bug: 223603970
Test: manual (verify albums are more centered) (see screenshots in bug)
Test: MediaControlPanelTest
Change-Id: Ibb3c8d9d22b30a642fef38b170c42cebdaec28cc