Update CODEOWNERS for Chrobalt

Issue: 360225419

.github/CODEOWNERS

@@ -1,20 +1,4 @@
-# Code owners are automatically requested for review when someone opens a pull
-# request that modifies code that they own. Code owners are not automatically
-# requested to review draft pull requests.
-#
-# For the full docs on CODEOWNERS, see:
-# https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/about-code-owners
-
-# Metrics owners
-/cobalt/browser/metrics/ @joeltine
-/components/metrics/ @joeltine
-/tools/metrics/ @joeltine
-
-# Monitoring for merges to Chromium upstreams
-/base/ @youtube/cobalt-3p-repository-owners
-/build/ @youtube/cobalt-3p-repository-owners
-/crypto/ @youtube/cobalt-3p-repository-owners
-/net/ @youtube/cobalt-3p-repository-owners
-/third_party/abseil-cpp/ @youtube/cobalt-3p-repository-owners
-/third_party/modp_b64/ @youtube/cobalt-3p-repository-owners
-/url/ @youtube/cobalt-3p-repository-owners
+* @youtube/cobalt-3p-repository-owners
+/.github/ @youtube/cobalt-committers
+/chrobalt/ @youtube/cobalt-committers
+/starboard/ @youtube/cobalt-committers