Allow Protected Audience APIs to match subdomains

The URI validation in Protected Audience APIs currently requires a given
URI to exactly match an AdTechIdentifier.  Added more in-depth
validation to allow valid subdomains to be matched against hosts.

This change affects CustomAudience fields, AdSelectionConfig fields,
generated URIs from impression and event reporting, and fetched URIs
from the Custom Audience daily update.

Test: atest AdServicesServiceCoreUnitTests
Bug: 279446930
Change-Id: I9d82411fb9958f9062325d635c21fa2ce78f359e
2 files changed