Move ART gtests to their own ART MTS shard.

Introduce an additional shard (shard 03) and move ART gtests from
their current shard (shard 00) to this new shard, in order to decrease
the run time of shard 00.

Test: m mts && mts-tradefed run commandAndExit mts-art
Test: m mts && mts-tradefed run commandAndExit mts-art-shard-03
Bug: 234651517
Bug: 182575630
Change-Id: I05d9650b0883c19a01e900efba83799277f29878
1 file changed