Disable vacation messaging

[BenHenning]

Explanation

Now that the team is back for reviews, the automated PR message is no longer needed. This PR keeps the messaging support, but disables the vacation-specific message used over the last few weeks.

Essential Checklist

• The PR title and explanation each start with "Fix #bugnum: " (If this PR fixes part of an issue, prefix the title with "Fix part of #bugnum: ...".)
• Any changes to scripts/assets files have their rationale included in the PR explanation.
• The PR follows the style guide.
• The PR does not contain any unnecessary code changes from Android Studio (reference).
• The PR is made from a branch that's not called "develop" and is up-to-date with "develop".
• The PR is assigned to the appropriate reviewers (reference).

For UI-specific PRs only

N/A -- CI workflow change

[github-actions]

Thanks for submitting this pull request! Some main reviewers
have taken time off for the next few weeks, so it may take a
little while before we can look at this PR. We appreciate your
patience while some of our team members recharge. We'll be fully
returning on 4 January 2021.

[BenHenning]

@seanlip @rt4914 @anandwana001 PTAL. I'll merge this once I get one approval; just sending it broadly to increase chances of faster turnaround so that this message gets disabled.

[seanlip]

Hi Ben -- left one suggestion, thanks!

[seanlip]

Perhaps worth adding a comment here saying something like "If situation XXX occurs, do YYY to turn this on." (It doesn't seem obvious to me as a possible future contributor that the natural thing to do is to drop this line altogether.)

[BenHenning]

Good suggestion--done.

[anandwana001]

LGTM, agreed with Sean's comment about adding a comment to make true/false thing more understandable.

[seanlip]

Thanks, LGTM

[BenHenning]

Thanks @seanlip & @anandwana001. Enabling auto-merge.