"pb namespace"

[Roy Williams]

Howdy,

In Nov 2020 protobuf reserved the namespace `pb` for protobuf to move to in the future (https://github.com/protocolbuffers/protobuf/blob/bd9a7104e11740e4bcfbde46c190c2d908ef331a/src/google/protobuf/port.h#L42-L44).  This is very problematic for us as all of our protobufs are in the `pb` namespace and breaks our ability to upgrade.  This seems to be quite a common pattern in the industry - https://github.com/search?l=Protocol+Buffer&p=1&q=%22package+pb%22&type=Code .

If at all possible can we roll back that change?  I suspect it has the potential to break a huge number of users beyond just us.

Thanks,

Roy