[Tooling] Update App Center Distribution Group used by Installable Builds

[AliSoftware]

Note: This is a replication of a similar PR done on WooCommerce-iOS a while ago

Note: See internal request pdnsEh-Of-p2

Description

This PR should resolve access issues by distributing prototype builds to the Collaborators group on App Center, which is the group associated with our internal automation.

• WPiOS-One-Offs app (line 274): this PR updates the destinations parameter of the appcenter_upload call to "Collaborators"
• jetpack-installable-builds app (line 327): No change. The appcenter_upload call already specified "Collaborators" for its destinations parameter
• WP-Internal app (line 225): No change. The appcenter_upload call didn't specify a destinations parameter at all, hence defaulting to "Collaborators" already.

Testing instructions

Note that the build associated with this PR is distributed to the Collaborators group.

[wpmobilebot]

You can test the changes in WordPress from this Pull Request by:

• Clicking here or scanning the QR code below to access App Center
• Then installing the build number pr19778-6770abb on your iPhone

If you need access to App Center, please ask a maintainer to add you.

[wpmobilebot]

You can test the changes in Jetpack from this Pull Request by:

• Clicking here or scanning the QR code below to access App Center
• Then installing the build number pr19778-6770abb on your iPhone

If you need access to App Center, please ask a maintainer to add you.

[AliSoftware]

Proof it worked as expected:

WPiOS-One-Offs releases on AppCenter were released to All-users-of-WPiOS-One-Offs before, but will now be distributed to Collaborators:

jetpack-installable-builds releases on AppCenter were always released to Collaborators already:

[twstokes]

👋 @AliSoftware - should this target the 21.4 milestone? Currently the 21.4 release branch hasn't been cut from trunk.

[AliSoftware]

Hey @twstokes, very good question!
Tbh I was quite lost when I had to choose a milestone for that PR, because the dates associated with the GitHub milestones were incorrect and hadn't been fixed to account for our modified schedule due to holiday break, so I was a bit confused as to which one to pick. (see p1671048679087929-slack-C02KLTL3MKM)

I just checked the current versioning and it seems that at the time of speaking, 21.3 is the one in code freeze while 21.4 is the one in trunk, so indeed targetting 21.4 is likely what I meant instead 👍 Thanks for the correction!