Clarify where GPL-v2 and GPL-v2-with-classpath-exception apply

This change removes unnecessary licenses from the top-level Android.bp
and adds a separate Android.bp for ojluni tests which are GPL-v2 (no
classpath exception).

Bug: 255273691
Test: m lint-check
Change-Id: Ib74da3ce8cf1a244d3b628e736903c093a523182
4 files changed