Use truth-prebuilt-jar instead of truth-prebuilt.

truth-prebuilt ends up depending on android stubs, but running
libcore tests shouldn't depend on android stubs.

Required after:
https://android-review.googlesource.com/q/topic:%22apistubs_cleanup%22

Test: art/tools/run-libcore-tests.sh
Change-Id: Iabc2076dcd5b7896ee0aec8046055308e8d743ef
1 file changed