GMap field is blank when downloading webform result

Problem/Motivation

• GMap field is blank when downloading webform result

Steps to reproduce

• Install the webform and webform_gmap_field modules
• Create a new webform
• Add a GMap field in the webform
• View the webform, select a location on the map and submit
• Go to the result tab, the submission is recorded
• Go to the download tab and download the results as, for example, CSV file
• Open the downloaded CSV file, the GMap field shows up blank

Proposed resolution

• Implement the buildExportRecord method in WebformGmapField.php