[lldb] Use SBProcess::Continue instead of 'run' command in TestTargetAPI.py

This test is flaky on Green Dragon as it often fails when the process state
is "Invalid" in the assert:
    self.assertEqual(process.GetState(), lldb.eStateExited)
It seems this is related to just doing "run" which apparently invalidates
the Target's process in case it's still running and needs to be restarted.
Just doing 'continue' on the process (and ignoring the error in case it already
finished) prevents that and makes this consistently pass for me.

Just pushing this out to get Green Dragon back online.