Implement #817 (#821)

* Rename .java to .kt

* Initial Workmanager migration

* Fix notification

* *

* Add timepicker

* Fix TimePicker layout

* Use 12H clock

* *

* Fixup

gradle.properties

@@ -20,4 +20,3 @@ org.gradle.parallel=true
 org.gradle.caching=true
 android.useAndroidX=true
 android.enableAppCompileTimeRClass=true
-android.experimental.enableNewResourceShrinker.preciseShrinking=true