GPL requires providing the source code via a medium customarily used for software interchange. Deliberately making it inconvenient by using a medium no longer customarily used for software interchange is a GPL violation. Google Drive is already an unusual way to distribute software.

Google is already failing to provide the Pixel kernel drivers in the preferred form for modification. Their kernel build system uses Git commands but yet they aren't providing the Git repositories it expects to be there. They had to provide a repo metadata file as a workaround but it's not the same since the revisions of the code aren't set properly in the resulting build.

Google is arguably already violating the GPL. They're deliberately making it inconvenient and are adding deliberate delays through requiring manual handling of the requests.