don’t place sub-template into main template when no value is present

* added logic that will not place the sub-template for {{Creator}} or
  {{Institution}} into the main template if the corresponding fields
  have no values.

Bug: 63646
Change-Id: Ica75e892edaf3c1069da01ac695fa28607e35435
Merge "don’t place sub-template into main template when no value is present"