Backport v2022<-v2023: Wait for AUM logs to be flushed

Backport !44 (merged)

Under some scenarios, the logs for the AUM restart take longer to appear, causing that the cursor is saved before them. Under this situation the test might think that AUM was restarted after a crash.

In order to have a reliable way of check logs wait for AUM logs to be flushed after restart it.

Also, fix the use of journalctl with cursor, to avoid missing log entries.

infrastructure/apertis-issues#146 (closed) infrastructure/apertis-issues#217 (closed)

Signed-off-by: Walter Lozano walter.lozano@collabora.com