Backport of "videoaggregator: always convert when user provides converter-config" into 1.20
requested to merge tpm/gstreamer:backport-mr-2746-into-1.20-videoaggregator-fix-converter-config into 1.20
Backport of !2746 (merged) "videoaggregator: always convert when user provides converter-config".
Commits:
- 56ec817b videoaggregator: always convert when user provides converter-config