Pre-flight checklist in German
Various fixes and improvements

- typos fixed
- made more app code i18n'ed
- completed German translations (where possible)
- set `translatable=false` for pref keys and not translatable items
Build fix: (re)added missing escape
Rearranged strings to groups
Improved Droneshare translations
'...'s replaced, flattened German translation XML, removed translated `app_title`
Removed orphaned/unused 'fragment_alert_dialog', better Droneshare translations
Better German translation for survey WPs
Merged getString(int) and String.format(String, Object...)
Oops! Forgot the formatted value for English in previous commit.
Merge pull request #1345 from zumbrunnen/i18n_updates

Some more I18n updates