Backport of "element: Fix requesting of pads with string templates" into 1.20
requested to merge tpm/gstreamer:backport-mr-2635-into-1.20-element-request-string-template-pad into 1.20
Backport of !2635 (merged) "element: Fix requesting of pads with string templates".
Commits:
- a3cbaa82 element: Fix requesting of pads with string templates