DO NOT MERGE: Allow Ephemeral apps to load code from /data/data for 8.0

This restriction causes issues with dynamite.

Since untrusted_v2_app was about enforcing this constraint put installed
v2 applications back into the normal untrusted_app domain.

CP from commit fe836817 & adapts for 8.0

Bug: 64806320
Bug: 69057841
Test: make cts

Change-Id: I3abf3ade64aaf689039a515de642759dd39ae6f7