enums in dimension attributes.

enums in resources were only read for integer attributes. This change
parses the enums for dimension resources also. This also means that we
don't have to hardcode the resolution for match_parent and wrap_content.

TODO: Fix this for all resource types.

Bug: http://b.android.com/75285
Change-Id: I86752b2322ea017499942a87568ba5c54b8654e4