Start publishing with Gradle metadata

Start publishing with Gradle metadata (.module files). At the moment androidx.test only pubishes with .pom files.

By default gradle looks for .module files (https://docs.gradle.org/current/userguide/publishing_gradle_module_metadata.html#sub:interactions-other-build-tools) so if they are not there it ends up adding a second request for pom files.

Start by locating the repository's Gradle publication configuration and compare its current POM-only output with Gradle's linked metadata publishing documentation. Confirm that publication also produces .module files and that the extra POM request is no longer needed.

Written by the indexing model from the issue text.