This commit makes creating new RestoreSets explicit.
Initializing a backup transport now actually cleans its data as the AOSP
documentation demands. This should be fine as we usually do a fresh
backup after a new initialization.
Contrary to before, an initialization does not create new RestoreSets
anymore, but works within the existing set. For now, only manually
choosing a new storage location creates a new RestoreSet.
Fine-grained progress reporting causes apps to show up twice which is
confusing. Also @pm@ metadata and opt-out APKs are too much detail for
normal users. So we decided to only show a percentage in the progress
notification.
When the backup finished, the app now shows "x of n apps backed up"
which is more positive when the previous negative message of how many
apps were not backed up.
Some further minor tweets were done to app counting to report proper
totals.
This adds @pm@ record backup and APK backup of opt-out apps to the
progress reporting since these two operations are slow when using a
cloud storage SAF backend.
Loading cursors can happen with cloud-based documents providers
such as Nextcloud.
When they return a cursor that is still loading,
we might continue with stale information.
So now we wait for a loading cursor to be fully loaded
before continuing.
This should also affect apps that have other errors during the backup
process, but it does not affect apps that opt-out of backup completely.
First part of #65
Apps that have nothing to back up start a backup but then get a call to cancelFullBackup()
and never even call finishBackup().
Do not write metadata for such apps, the call got moved to finishBackup().
These might return outdated or now content when queried,
then check their cloud storage and report back with up-to-date content.
We now detect this (when looking for backups on newly setup storage)
and wait until the content has been loaded before acting on the
response.
This is affecting and was tested with NextCloud.
