Wrong button text color in symptom flow (EXPOSUREAPP-4207) #1911

* Text Color changed

* Text Color changed for calendar screen

* removing build.gradle changes that carried over from 1.10

* lint fix

* adapt color scheme to be consistent and high contrast

* klint

Co-authored-by: Ralf Gehrer <ralfgehrer@users.noreply.github.com>
Co-authored-by: Chilja Gossow <49635654+chiljamgossow@users.noreply.github.com>
Co-authored-by: chilja <chiljamgossow@gmail.com>