fix broken tests

With the Update to Android API 34 / Android 13 and Java 17 Java Reflection was restriced, which we rely on in many tests by using Powermock to mock Android dependencies. In many cases we've wrapped Android specific APIs in static methods of Helper classes and used Powermocks mockStatic. That approach is broken and to fix the tests, we will have to adapt partly the architecture of the app as well as to rewrite some tests.