Add support for graceful termination of agent pods when deploying via Helm chart

[onematchfox]

PR Description

Adds support for setting terminationGracePeriodSeconds and lifecycle on agent pod/container when deploying via the Helm chart here. This is useful to ensure graceful shutdown of agents, for example, to ensure that traces are not dropped when using tail-based sampling.

Which issue(s) this PR fixes

Notes to the Reviewer

PR Checklist

• CHANGELOG.md updated
• Documentation added
• Tests updated
• Config converters updated

[github-actions]

This PR has not had any activity in the past 30 days, so the needs-attention label has been added to it.
If you do not have enough time to follow up on this PR or you think it's no longer relevant, consider closing it.
The needs-attention label signals to maintainers that something has fallen through the cracks. No action is needed by you; your PR will be kept open and you do not have to respond to this comment. The label will be removed the next time this job runs if there is new activity.
Thank you for your contributions!

[github-actions]

This PR has not had any activity in the past 30 days, so the needs-attention label has been added to it.
If you do not have enough time to follow up on this PR or you think it's no longer relevant, consider closing it.
The needs-attention label signals to maintainers that something has fallen through the cracks. No action is needed by you; your PR will be kept open and you do not have to respond to this comment. The label will be removed the next time this job runs if there is new activity.
Thank you for your contributions!