Memorized cell location database (from location menu) is not correctly backed up/restored by seedvault

**Describe the bug**
When restoring a seedvault backup of microg companion, the database of memorized cell tower/wifi access point locations is incorrectly empty.

**To Reproduce**
Steps to reproduce the behavior:
1. On phone 1, populate the wifi/cell tower database
2. back it up with seedvault
3. import the backup on phone 2
4. micro g companion > location > three dot menu > export database > the database is empty

**Expected behavior**
The database of the previous phone should be restored

**System**
Android Version: phone1: 15, phone2: 16
Custom ROM: phone 1: Calyxos 6.7 phone2: Calyxos 7.2

**Additional context**

Seedvault reports backup of microg companion with a green tick. This suggests that the data voluntarily reported by microg companion as backup does not include all the data worth a backup. https://github.com/seedvault-app/seedvault/wiki/Known-Issues#many-apps-dont-test-or-even-disable-backups

Start by tracing the backup data reported by microG Companion and the persistence of the memorized cell-tower and Wi-Fi locations. Reproduce the phone-to-phone restore, then use Location > the three-dot menu > Export database to verify the restored database is populated. Done means the memorized locations from the first phone are present after restoration.

Written by the indexing model from the issue text.