Add traffic_controller, networkstats, netd_updatable tests to MTS.

In order to get counted by mts code coverage, these native tests need to
be run as part of mts.

Bug: 233904825
Test: m mts && mts-tradefed run mts-tethering-coverage
Change-Id: I79313197b146c7043ffb5e164faa46c2e16dd1d2
5 files changed