Restrict R8 -libraryjars refs for stable targets

The current R8 dex pipeline gathers transitive header jars to avoid
issues with missing class definitions. While this is benign for
platform targets not using a stable SDK, it can introduce issues
for stable targets (e.g., duplicate class defs for mainline framework
modules).

Bypass this transitive jar referencing for such targets that should
reference explicit, stable, stub API libraries. A follow-up change
will resolve specific issues with mainline system server targets.

Bug: 360905238
Test: m
Change-Id: I11a136d33ca9dd0dfff436c7045bf1807d17b1e7