* Replaced KeyFileDownloader.kt in favor of KeyFileSyncTool.kt.
Supports new logic for more frequent downloads
First draft.

* Change "country" to location, which is more fitting.

* Split sync success tracking into days and hours, track them separately.

* Fix stale location data not being cleaned up.

* Test fragment, first drafts.
Remove 24 hour mode options, no longer used.

* Implemented metered connection check for hourly key download.

* Provide timeout values for download transaction and individual downloads via app config.

* Add clear+download actions, and current network state display to the key download test fragment.

* Complete unit tests for KeyDownloadTool.kt

* Complete unit tests for FlowPreference and DownloadConfigMapper-

* Unit tests for day and hour sync tool.

* Complete tests for KeyPackageSyncTool.kt

* klint & detekt <3

* Fix tags and commented out code (the deletion behavior is covered by `getting completed keys`

* Fix text typo.

* Sync tools need to tell what (if) new packages have been downloaded.

* Interval checks for exposure detection.

* Use the ENFClient, avoid direct access to the calculation tracker.

* Remove defensive check "wanted countries"/"available countries" to reduce server hits.

* CalculationTracker's timeout should come from the AppConfig (androidExposureDetectionParameters.overallTimeoutInSeconds)

* Add test to confirm that we delete stale locations.

* Finished key packages test screen.
Introduced some boilerplate code to make async diffutils easier to use (will help us with the homefragment later on).

* Remove ETag fallback behavior, missing ETag is such an edge case that we should throw.

* Check valid max and min config values.

* Fix linting issues.

* Address PR comments.

* EXPECT_NEW_*_PACKAGES should be based on the package time data, not the download creation timestamp.
The downloads creation timestamp can be subject to race conditions.

* Fix overflow due to time addition with Long.MAX_VALUE

* Clean up tests

* Don't crash the task if we can't get today's hour index.
(Makes timetravel testing difficult, and a real abort reason would be a crash on the day index)

* Display errors (don't crash) when running manual keysync from the test menu.

* Fix last day/hour sync result success state not being updated.

* Change Key download task collision mode from ENQUEUE to SKIP_IF_SIBLING_RUNNING.

* Rename CalculationTracker to ExposureDetectionTracker

* Rename `forceSync` to `forceIndexLookup`.

* Remove outdated comments.

* Spell out viewholder.

* Move `maxExposureDetectionsPerUTCDay == 0` into it's own check.

* Change test menu metered connection button behavior. It's now a button that "fakes" the connection status to metered.
It's now also part of the `TestSettings` and the connection state is faked for the `NetworkStateProvider` class which may be reused.

* Change test menu metered connection button behavior. It's now a button that "fakes" the connection status to metered.
It's now also part of the `TestSettings` and the connection state is faked for the `NetworkStateProvider` class which may be reused.

* Dry sync/error logging call.

* Improve parameter naming, it's target locations, not available locations.
The app config alone determines which locations we try to sync.

Co-authored-by: BMItter <46747780+BMItter@users.noreply.github.com>