common: Use a subtree instead of a local common folder

This includes the fix common@82a22234 needed to make sure that the test doesn't fail anymore

https://phabricator.apertis.org/T8841

common/run-aa-test

@@ -74,7 +74,7 @@ TMP_DIR=$(mktemp -d)
 trap "rm -rf $TMP_DIR; exit" EXIT
 
 # Log start time
-START_TIME=$(date +"%F %T")
+START_CURSOR="$(journalctl --output-fields=__CURSOR --output=json -n1 | jq -r '.__CURSOR')"
 
 if [ "${LAUNCH_DBUS}" = "True" ]; then
 	# Start a new D-Bus session for this test
@@ -132,7 +132,7 @@ if [ "${UID}" != "0" ]
 then
 	JOURNALCTL="sudo journalctl"
 fi
-${JOURNALCTL} -S "${START_TIME}" -t audit -o cat > ${AUDIT_FILE}
+${JOURNALCTL} --after-cursor "${START_CURSOR}" -t audit -o cat > ${AUDIT_FILE}
 
 echo "#=== ${TEST_TITLE} ==="