Trade-fed: Wrap the test commands in trivial chroot

Remove the apex installation step within tradefed,
which required device reboot and forced us to depend
on the testing apex (which we want to remove).

Add naive chroot environment for each executed test,
which just updates the content of ART apex directory
(including adding debug versions of ART binaries).

Bug: 147812905
Flag: TEST_ONLY
Test: atest ArtTest
Change-Id: Ib6f321ad28b469a24f3d495cf0791f45829b0bfb
2 files changed