Convert "module loader plugin" Gradle script into a proper Gradle plugin #138756
Description
Description
The module_plugin_loader.gradle file is a Gradle script. It should be a Gradle plugin instead, for all reasons mentioned in #121552 and #125009.
More context
For an example of 2 similar conversions that already happened, see:
This issue is about doing the very same thing but for module_plugin_loader.gradle (including providing backward compatibility).
See also #135392, which should be updated once this issue is fixed.