v3.1.0: OpenTracks

Changes:
- Added show track in map apps (tested with OsmAnd and Maps.ME)
- Added while tracking, show track statistics without unlocking the device
- Removed landscape mode for track detail view (was buggy)
- Removed search suggestions history

Bugfix:
- Request storage permission for import all/export all

Developer:
- Upgrade to Gradle 5.6
- Do not minify release builds
