Adjust low risk card (EXPOSUREAPP-4836) #2238

* Replace strings "on one day" to "on 1 day" for low risk card

* Change content description of low risk card

* Adapt low risk card - display date when last encounter occurred - similar to high risk card

* Update Corona-Warn-App/src/main/res/values-de/strings.xml

Co-authored-by: Sabine Loss <44154356+SabineLoss@users.noreply.github.com>

* Update Corona-Warn-App/src/main/res/values/strings.xml

Co-authored-by: Sabine Loss <44154356+SabineLoss@users.noreply.github.com>

* Update strings.xml

* Rename input parameters of LowRisk data class from c to context

* Fix instrumentation tests

Co-authored-by: Sabine Loss <44154356+SabineLoss@users.noreply.github.com>
Co-authored-by: harambasicluka <64483219+harambasicluka@users.noreply.github.com>