Lint/Format check fails when using the protobuf-gradle-plugin and non-main-sourceset protos

[berksean]

With this previous issue, a breaking change with the protobuf-gradle-plugin and bug was fixed to remove linting/formatting of generated code.

That fix addressed issues of performing linting of proto files imported from other dependencies. However, it turns out that the protobuf-gradle-plugin will generate multiple build-extracted/protos/... directories when non-main-source-set configurations are used (e.g. testImplementation(<some GAV>)).

This results in the weird broken behavior similar to the previous issue.

I'll put together what I believe to be a straightforward fix that removes the build-extracted--protos- prefixed directories from the set of sources that need to be linted.