Show data restricted apps, unify strings.

Always show apps with background data restricted, even when not
used in selected time period.  Combine measurement disclaimer into
single string, and only show for mobile networks.  Unify limit
dialog string.

Bug: 6007276, 5505010, 5495020, 5456087
Change-Id: I0ec307b330838dc9528d7e63e0ac1edd14ba122c