Replace active tracing days with days since installation (EXPOSUREAPP-5170) (#2522)

* Added new strings.

* Implemented first install time logic.

* Adapted screens to first install time.

* Fixed layout issues in tracing settings.

* Instrumentation test fix.

* Addressed PR comments.

* Removed mstodays transformation.

* Added missing daysSinceInstallation value.

* Removed unnecessary constraint layouts.

* Fixed constraints.

* Unified text styles to subtitles.

* Over 14 days text displayed from 14 days onwards.

* Minor UI adjustments.

* Risk card not showing days since install when lowe risk encountered.

Co-authored-by: Ralf Gehrer <ralfgehrer@users.noreply.github.com>
Co-authored-by: Juraj Kusnier <jurajkusnier@users.noreply.github.com>