App restrictions schema and parser

Documented the restrictions schema in RestrictionsManager docs.
Added a parser to read the meta-data and XML file on the device.
Added more types and methods in RestrictionEntry to accomodate some
new types and construction modes.
Added a styleable for restriction attributes.

Slight tweak to permission response params.

Bug: 14582645
Change-Id: I193d1162741d110c100831cab33b48e2baf7426c