Switch from googapis to google-api-proto crate

[mfelsche]

Describe the problem you are trying to solve
I am trying to update prost and tonic dependencies in our Repo, but this failed due to e.g. googapis depending on prost 0.9.
The reporsitory https://github.com/mechiru/googapis didn't get any updates anymore for a long time.
By accident we found: https://github.com/mechiru/google-api-proto which is the successor and should be used as a replacement. It is recently maintained and depends on prost 0.10 with an open PR to update to 0.11.

Describe the solution you'd like

Unblock all the dependency upgrades. 🥳

[mfelsche]

cc @dak-x I think this would unblock your PR #1818 would it?

[darach]

Assigning to me as it became necessary to update all the gRPC based connectivity in a single work stream.