Build ART's Checker tool with an embedded launcher.

Making this Python script self-contained may help with some Checker
test failures seen in continuous testing on ATP.

Test: atest --test-mapping art:presubmit
Bug: 236120431
Bug: 240276270
Change-Id: Iad5824001a738e6610ca2292a71bd10a0968c21c
2 files changed