I can upload drone imagery using the Street View app, but they are published as dots. The spacing is about 1 meter apart, but even after 2 weeks still show without blue line.
I know a many people have upload drone footage to GSV (I’m looking at @KikoTrekView).
It seems drone pictures are allowed, but this is not explicitly stated anywhere I can find.
Coincidently, in the Google Street View support portal it appears the company are working something…
Whilst this doesn’t answer your question, it seems Google are at least thinking about a solution to drones.