Rename setup_google_drive_connection -> setup_gdrive_connection.

[JoeZiminski]

This PR renames setup_google_drive_connection to setup_gdrive_connection. The reason is that for all other API arguments it is refered to as gdrive rather than google drive, so this is gone for consistency. Alternatively, gdrive references could be changed to google_drive, but some of these arguments are already quite long. I think it gdrive is a pretty intuitive and easy-to-remember abbreviation. What do you think about this @cs7-shrey ?

[cs7-shrey]

It's a nice thought. I think we can rename other such variables too in interface.py. Like, google_drive_rclone_setup_process, terminate_google_drive_setup, etc.

[JoeZiminski]

Thanks @cs7-shrey good shout! Have updated