Fix release build.
Fix release build.

+ Decrease severity level of Lint error to warning.
+ Introduced by Android plugin v.3.2.1 in c48f1a100b1824be38c3438cae430221c36dd675.
+ Example of the original error: 'The layout "about_dialog" in layout-port
  has no declaration in the base layout folder; this can lead to crashes
  when the resource is queried in a configuration that does not match this
  qualifier [MissingDefaultResource]".

EventFahrplan/EventFahrplan,EventFahrplan/EventFahrplan