Docs on return type on two media constraints are misleading

Problem/Motivation

\Drupal\media\MediaSourceFieldConstraintsInterface::getSourceFieldConstraints says the return type should be

* @return \Symfony\Component\Validator\Constraint[]
   *   An array of validation constraint definitions, keyed by constraint name.
   *   Each constraint definition can be used for instantiating
   *   \Symfony\Component\Validator\Constraint objects.

But actually, its an array where the keys are validation plugin IDs and the values are options for the plugin.

Steps to reproduce

Proposed resolution

Update the documentation

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet