Add support for standalone ART gtests to MTS.

This change:
- adds standalone ART gtests to test suite `mts-art`;
- adds `MainlineTestModuleController` support to standalone ART
  gtests. This in order to have these tests run in a Mainline context
  only when the ART Module (either `com.google.android.art` or
  `com.android.art`) is installed on the test device.

(cherry picked from commit 6a2e6893290eac83f59dac4ec5bc10abf985ae10)

Test: m mts && mts-tradefed run commandAndExit mts-art
Test: m mts && mts-tradefed run commandAndExit mts-art-shard-00
Bug: 193218514
Bug: 167385698
Change-Id: I97d9c00b7c10debff8c63e4ae75f90da02be271c
Merged-In: I97d9c00b7c10debff8c63e4ae75f90da02be271c
12 files changed