Adding a fullScreen option for our Dialog component.

src/components/gpx-import/GpxImport.tsx

@@ -53,6 +53,7 @@ const GpxImport: Component = () => {
         open={filesToImport() !== undefined}
         title={t('gpxImport')}
         closeHandler={handleClose}
+        fullScreen
       >
         <Box
           sx={{