Show video thumbnail and download link in view
Add field_file_vid again, check mark exclude from display and this time don't use URL to File as formatter, use a different formatter that renders the video. 

Rearrange the fields



so that this new field is above the original field.

Now in your original field's rewrite results, use this as your 3rd line:

&lt;div class="gallery-video"&gt;{{ field_file_vid_1 }}&lt;/div&gt;