Update validate-modules (#20932)

* Update validate-modules

* Validates ANSIBLE_METADATA
* Ensures imports happen after documentation vars
* Some pep8 cleanup

* Clean up some left over unneeded code

* Update modules for new module guidelines and validate-modules checks

* Update imports for ec2_vpc_route_table and ec2_vpc_nat_gateway

lib/ansible/modules/cloud/openstack/os_nova_host_aggregate.py

@@ -14,13 +14,9 @@
 # You should have received a copy of the GNU General Public License
 # along with this software.  If not, see <http://www.gnu.org/licenses/>.
 
-try:
-    import shade
-    HAS_SHADE = True
-except ImportError:
-    HAS_SHADE = False
-
-from distutils.version import StrictVersion
+ANSIBLE_METADATA = {'status': ['preview'],
+                    'supported_by': 'community',
+                    'version': '1.0'}
 
 DOCUMENTATION = '''
 ---
@@ -80,6 +76,15 @@ RETURN = '''
 
 '''
 
+try:
+    import shade
+    HAS_SHADE = True
+except ImportError:
+    HAS_SHADE = False
+
+from distutils.version import StrictVersion
+
+
 def _needs_update(module, aggregate):
     new_metadata = (module.params['metadata'] or {})
     new_metadata['availability_zone'] = module.params['availability_zone']