Support Play Store release review process

[nid90]

Proposal

Support handling of the review process for Play Store releases.

What this achieves / problem(s) it solves

Tramline currently only handles the review process for App Store, it assumes that a release once promoted in Play Store will get released. We should handle approval/rejection from Play Store as well and finalize a release only after it gets approved and the distribution starts.

[nid90]

Currently, there is no documented way in which we can query the review status of a release using the Play Developer API.
Ref: https://issuetracker.google.com/issues/179708468

This can mean that once we start a release (promote a draft release) in the production track, the app may get rejected by Google even after the release (train run) has finished on Tramline.

We can come back to this once we integrate with post-release monitoring integrations and track the adoption rate of a particular release via those integrations. But, for now, we will have to ask our users to track the app review in Play Console.