ASL allow DataType to be easily compared (for lint annotation logic)

For Android Studio annotations checking, the linter can parse both the annotations and human-readable XML into corresponding ASL java objects (the human-readable XML parsing logic already exists in this java library). The linter can then nestedly iterate through the map of data categories and map of data types; if corresponding entries don't exist in the XML-parsed ASL or the DataType are not equal, it can be flagged to the developer.

Bug: 329902686
Test: Unit tests.
Change-Id: I3263157c57489dd782e70a385bc6f364b47655b4