fix(internal/gapicgen): restore fmting proto files (#4789)

This should be done pre-resetUnknownVersion check to reduce diffs
and release PRs generated post regen.

Author: codyoss

internal/gapicgen/generator/gapics.go

@@ -113,6 +113,11 @@ func (g *GapicGenerator) Regen(ctx context.Context) error {
 		return err
 	}
 
+	// Get rid of diffs related to bad formatting.
+	if err := gocmd.Vet(g.googleCloudDir); err != nil {
+		return err
+	}
+
 	if err := g.resetUnknownVersion(); err != nil {
 		return err
 	}