* Disable klint debug output to make it easier to find the actual error in the log.

* Setup jUnit5 & kotest.

* Add base classes for testing to setup log output.

* Introduce class `DeviceStorage` to check (or request on newer APIs) free space.

Rel. EXPOSUREAPP-2259

* Add test cases for failure modes.

* Make it obvious that the check should not be executed on the ui thread.

* Try fall back to legacy method if the API26+ version fails.
If that also fails, throw the exception and let the caller handle it.

* Wire up injection annotations.

* Remove unused mockito testing dependency.

* klint...

Co-authored-by: Matthias Urhahn <matthias.urhahn@sap.com>
Co-authored-by: Jakob Möller <jakob.moeller@sap.com>