Add validation test for new copyright (#32919)

* Update validation test for new copyright

Ensure new modules without the new copyright header fail
validation
Ensure existing modules without copyright in top 20 lines fail

* Add documentation of 108 error

Create label in developing modules documentation so that
the validation page can point to it

* Ensure new style copyright header passes test!

docs/docsite/rst/dev_guide/developing_modules_documenting.rst

@@ -30,6 +30,7 @@ All modules must have the following sections defined in this order:
   If you look at some existing older modules, you may find imports at the bottom of the file. Do not copy that idiom into new modules as it is a historical oddity due to how modules used to be combined with libraries. Over time we're moving the imports to be in their proper place.
 
 
+.. _copyright:
 
 Copyright
 ----------------------

docs/docsite/rst/dev_guide/testing_validate-modules.rst

@@ -69,6 +69,7 @@ Errors
   106       Import found before documentation variables. All imports must appear below
             ``DOCUMENTATION``/``EXAMPLES``/``RETURN``/``ANSIBLE_METADATA``
   107       Imports should be directly below ``DOCUMENTATION``/``EXAMPLES``/``RETURN``/``ANSIBLE_METADATA``
+  108       GPLv3 license header should be the :ref:`short form <copyright>` for new modules
   ..
 ---------   -------------------
   **2xx**   **Imports**

test/sanity/validate-modules/main.py

@@ -375,14 +375,24 @@ class ModuleValidator(Validator):
                 msg='sys.exit() call found. Should be exit_json/fail_json'
             )
 
-    def _check_for_gpl3_header(self):
-        if ('GNU General Public License' not in self.text and
-                'version 3' not in self.text):
+    def _check_gpl3_header(self):
+        header = '\n'.join(self.text.split('\n')[:20])
+        if ('GNU General Public License' not in header or
+                ('version 3' not in header and 'v3.0' not in header)):
             self.reporter.error(
                 path=self.object_path,
                 code=105,
-                msg='GPLv3 license header not found'
+                msg='GPLv3 license header not found in the first 20 lines of the module'
             )
+        elif self._is_new_module():
+            if len([line for line in header
+                    if 'GNU General Public License' in line]) > 1:
+                self.reporter.error(
+                    path=self.object_path,
+                    code=108,
+                    msg='Found old style GPLv3 license header: '
+                        'https://docs.ansible.com/ansible/devel/dev_guide/developing_modules_documenting.html#copyright'
+                )
 
     def _check_for_tabs(self):
         for line_no, line in enumerate(self.text.splitlines()):
@@ -1118,7 +1128,7 @@ class ModuleValidator(Validator):
             self._validate_ps_replacers()
             self._find_ps_docs_py_file()
 
-        self._check_for_gpl3_header()
+        self._check_gpl3_header()
         if not self._just_docs():
             self._check_interpreter(powershell=self._powershell_module())
             self._check_type_instead_of_isinstance(