Story 436: Use file name for images with descriptions with templates

Modified juliusz's original patchset rather than abandoning it
since we now want a slight variation of this

Renders description as filename
Minus File: prefix, date and extension.

Now avoids unnecessary api call

Also addresses:
Bug: 45579

Change-Id: Ie1fc7f0591b6312fbdd45d9889895d74b25ded02
Merge "Story 436: Use file name for images with descriptions with templates"