Backup process keeps on going even if Signal app process is killed, despite restarting the device

[kaosmaja]

• I have searched open and closed issues for duplicates
• I am submitting a bug report for existing functionality that does not work as intended
• I have read https://github.com/signalapp/Signal-Android/wiki/Submitting-useful-bug-reports
• This isn't a feature request or a discussion topic

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Bug description

Related to #13664, but sending a message that causes hanging of the backup process as main drive memory runs out and doesn't self-terminate unlike usual. Then killing the Signal process through the settings the backup process continues to consume primary drive space continuously, persisting even through restart. Finally resolved the situation by deleting the old backup.

Steps to reproduce

• First replicate the steps of Daily backup hogs all storage even if it will fail the backup #13664
• When the backup process has started, try to send a message.
• The process starts hanging and does not exit at any point unlike when it normally runs out of primary drive space
• Space freed by deleting apps from the device to free up space for the debug didn't work because the backup process immediately hogged it for itself, staying at 0B.
• Restarting the phone initially freed up space, but within seconds the backup process resumed hogging all the primary storage space.
• Finally stopped hogging primary storage space when the old backup was deleted.

Actual result: Backup process lives on through forcefully shutting down the app through the settings.
Expected result: Forcefully killing the process through the app shuts down the backup process too.

Screenshots

N/A: Cannot do screenshots when there isn't space on the primary drive.

Device info

Device: XQ-AS52
Android version: 12
Signal version: 7.13.4

Link to debug log

N/A: Cannot get link until memory is cleared