Introduce a new OkHttp test module for ART MTS.

This change adds ART MTS test module `MtsLibcoreOkHttpTestCases`. This
test module is similar to `CtsLibcoreOkHttpTestCases`, but is used to
test the ART Mainline Module (via ART MTS), while
`CtsLibcoreOkHttpTestCases` is used to test the Conscrypt Mainline
Module (via Conscrypt MTS) and is of course also part of CTS.

(cherry picked from commit eb819308b4cb75cf75d39ef15864c10331581a57)

Test: atest MtsLibcoreOkHttpTestCases
Test: m mts && mts-tradefed run commandAndExit mts-art
Test: m mts && mts-tradefed run commandAndExit mts-art-shard-02
Bug: 193218514
Bug: 167385698
Change-Id: Ic4ced687ec3e4f87894ee475700e8a0a2fcdf0f2
Merged-In: Ic4ced687ec3e4f87894ee475700e8a0a2fcdf0f2
3 files changed