Convert libcore java to Android.bp

See build/soong/README.md for more information.

Test: m -j checkbuild
Test: classes.dex for core-oj is identical
Test: classes.dex for core-libart only has extra bridge methods (b/65645120)
Change-Id: I0f81937dcc6efba87e7f61b2d5840b18068cd587
8 files changed