Add duration field in query=imageinfo&iiprop=dimensions

If the file has a duration (e.g. an audio or video file), include
it in the list of dimensions returned. Do not include anything
for still media (normal pictures).

This affects both query=imageinfo and TMH's query=videoinfo.

Bug: 55941
Change-Id: If172a1cbaca08bff2eb709f6c829985b28b0200d
Merge "Add duration field in query=imageinfo&iiprop=dimensions"