Expose AppFunctionUriValueConstraint as a public API

Removes the LIBRARY_GROUP restriction from AppFunctionUriValueConstraint.

Relnote: Exposed `AppFunctionUriValueConstraint` as a public API.
Test: ./appfunctions/local_tests.sh
Bug: 552477537
Change-Id: I750702dcd86703ff2e493d4918686e83dc98b891