fix: promtail parser for azureeventhubs message without time field

[andriikushch]

What this PR does / why we need it:

The promtail parser for azureeventhubs ignores records that doesn't contain the time field.

• This change accepts such records if they contain the timeStamp field instead.
• For the parsed time, the location is set to the UTC

Which issue(s) this PR fixes:
Fixes:

• Logs with category "ApplicationGatewayFirewallLog" does not have proper category label in Loki #14176

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
  • Note that Promtail is considered to be feature complete, and future development for logs collection will be in Grafana Alloy. As such, feat PRs are unlikely to be accepted unless a case can be made for the feature actually being a bug fix to existing behavior.
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• For Helm chart changes bump the Helm chart version in production/helm/loki/Chart.yaml and update production/helm/loki/CHANGELOG.md and production/helm/loki/README.md. Example PR
• If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR

[Kapsztajn]

Can this pull request be merged? @andriikushch

[trevorwhitney]

Looks good, would you be open to my one suggestion regarding getTime()?

[andriikushch]

Looks good, would you be open to my one suggestion regarding getTime()?

@trevorwhitney, I have merged the suggestion 👍 and added the test. Could you please take a look once again at the latest changes and I think we can merge it then 😃

[andriikushch]

Can this pull request be merged? @andriikushch

Hi, @Kapsztajn 👋 It is merged now.