Summary:
These build failures only happen with GCC opt which I didn't test before submitting the GCC 10 upgrade.

UPB inside of GRPC has an issues with GCC-10 and this disables the relevant warnings.

Test Plan: N/A

Reviewers: oazizi, philkuz, #engineering

Reviewed By: oazizi, #engineering

Differential Revision: https://phab.corp.pixielabs.ai/D5709

GitOrigin-RevId: eb6524f5985ae5d6cea1601df73107a6b02908de