Fix test to not expect ordering of events across threads

2246-trace-stream tests for events on main and a test thread. There can
be some non-determinism in the order of events across threads. Fix the
test to print events corresponding to the test thread followed by main
thread.

Bug: 275117853
Test: art/test.py -t 2246
Change-Id: Ifaf91693c91301dab03c213c227df2866318961d
4 files changed