WorkManager
The Android library for background work that must run eventually, even after the app closes or the phone restarts.
Definition
A Worker holds the work and a WorkRequest says when it may run: constraints such as network or charging, a backoff policy for retries, and input data. WorkManager stores requests in its own database and schedules them within Android's battery rules, so they survive process death and reboots. Unique work prevents duplicates; expedited and foreground work cover urgent or long user-visible jobs.
In practice
A review is saved locally and an UploadReviewWorker with a CONNECTED constraint sends it whenever the phone is online.