Audit Code for `anypb.New` Usage

[danehans]

Instances of anypb.New should be replaced with utils.MessageToAny. See #10684 (comment) for additional context.

[timflannagan]

I ran into this recently as well. We can add a linter that enforces this. Typically I'll hold off on tackling good first issues, but we'll need to change some of this with the lambda work, so I'll throw up a quick PR.