Add isColorType to TypedValue

There's a lot of places that used TypedValue.TYPE_FIRST_COLOR_INT and
TypedValue.TYPE_LAST_COLOR_INT, and I'd like to propose that it's enough
of an implementation detail that it should have a dedicated public
method to query it.

Fixes: 114126626
Test: CTS tests to be added
Change-Id: I4d2a927cc3d2e999985d7e1c9b647d513fff53fc