Load-balance gcstress and gcverify ART test configurations.

Configuration art-gcstress-gcverify is sometimes hitting the build
timeout. Move 'interpreter', 'optimizing', and 'jit' coverage to other
gcstress configurations to balance the load among builders.

Test: art/test/testrunner/run_build_test_target.py -j30 art-gcstress-gcverify
Test: art/test/testrunner/run_build_test_target.py -j30 art-interpreter-gcstress
Test: art/test/testrunner/run_build_test_target.py -j30 art-optimizing-gcstress
Test: art/test/testrunner/run_build_test_target.py -j30 art-jit-gcstress
Bug: 74196452
Bug: 62611253
Change-Id: I7793256b284a56ce442d2d340405ca810a207dd8