Removes EphemrealResolverService and related

This change removes deprecated classes and constants that were not
renamed from ephemeral to instant prior to O. There were no
consumers of these APIs as correctly named alternatives existed and were
referenced in docs. No known consumers of these APIs exist on user
builds.

Fixes: 38137176
Fixes: 38121489
Test: manual; builds and instant apps launch
Change-Id: I982f8a6edc5668dd42cea65e52a1433ec8d6f8ef