Updated the ansible-galaxy docs (#52070)

* Updated the ansible-galaxy docs

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Updated the documentation that reflects the default branch that will be used for the `version` option in ansible-galaxy.

+label: docsite_pr

* Updated the documentation

As per the code (6d4307377f/lib/ansible/galaxy/role.py (L237))[ansible/galaxy/role.py] Defaults to the branch set as a default in the repository otherwise defaults to the master.

* Update docs/docsite/rst/reference_appendices/galaxy.rst

Co-Authored-By: anis016 <anis016@users.noreply.github.com>

docs/docsite/rst/reference_appendices/galaxy.rst

@@ -99,7 +99,7 @@ Each role in the file will have one or more of the following attributes:
    scm
      Specify the SCM. As of this writing only *git* or *hg* are supported. See the examples below. Defaults to *git*.
    version:
-     The version of the role to download. Provide a release tag value, commit hash, or branch name. Defaults to *master*.
+     The version of the role to download. Provide a release tag value, commit hash, or branch name. Defaults to the branch set as a default in the repository, otherwise defaults to the *master*.
    name:
      Download the role to a specific name. Defaults to the Galaxy name when downloading from Galaxy, otherwise it defaults
      to the name of the repository.