probes: delay NotifyDataSourceStopped until after local state teardown
probes: delay NotifyDataSourceStopped until after local state teardown

Per the comment, acknowledging the stop before actually destroying local
state means that when traced_probes runs as part of tracebox, it gets
killed while trying to reset tracefs files.

Change-Id: Iff7500e412fff9d86b1177ae673f2c5f5b7e4557
google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto