curtin-replay: update expected syslog identifier for curtin log lines

In the past, curtin log lines had the syslog identifier matching
"curtin_log.xxx". Nowadays, curtin commands are started via
systemd-run so they end up inheriting from the default
"subiquity_log.xxx" syslog identifier.

When updating the examples/curtin-*.json files, one must make sure to
filter out the entries that have the "subiquity_log.xxx" but are not
related to curtin invocations.

In the future, maybe we need to consider overriding the syslog
identifier when invoking curtin commands.

Signed-off-by: Olivier Gayot <olivier.gayot@canonical.com>

scripts/replay-curtin-log.py

@@ -31,7 +31,7 @@ def report(e, log_file: TextIO, event_identifier: str):
             rc = 0
         elif r == "FAIL":
             rc = 1
-    elif e['SYSLOG_IDENTIFIER'].startswith("curtin_log") and scale_factor < 10:
+    elif e['SYSLOG_IDENTIFIER'].startswith("subiquity_log") and scale_factor < 10:
         log_file.write(e['MESSAGE'] + '\n')