Update tracing config on git-master-art-host to use streaming

Tracing has three different modes: stream, file and ddms. Stream is the
most commonly used mode, so update the bots to run streaming when
running tracing config. In future, we should integrate all these modes
to use same underlying implementation.

Test: art/testrunner.py --trace --stream
Bug: 259258187
Change-Id: I6f881f296373a4a73a5554ba0306d6b852b8cdfb
4 files changed