[aws] Revert back to getting the AWS role name from the URI (#49428)

* Revert back to getting the AWS role name from the URI with a small change (#49113)

- The role name and instance profile name _can_ be different
- Change the delimiter to `:` for keys that are discovered through the JSON parsing (which is not a valid delimiter for AWS IAM role names), this delimiter is still converted to underscore
- Now checks for the existence of that delimiter to remove the cases where the JSON keys are appended to the role name to find the role name

(cherry picked from commit ff9b86f560)

* Changelog update

changelogs/fragments/49113-iam-role-arn-parsing-updated.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - ec2_metadata_facts - Parse IAM role name from the security credential field since the instance profile name is different

lib/ansible/modules/cloud/amazon/ec2_metadata_facts.py

@@ -466,8 +466,9 @@ class Ec2Metadata(object):
         new_fields = {}
         for key, value in fields.items():
             split_fields = key[len(uri):].split('/')
-            if len(split_fields) == 2 and split_fields[0:2] == ['iam', 'info_instanceprofilearn']:
-                new_fields[self._prefix % "iam-instance-profile-role"] = value.split('/')[1]
+            # Parse out the IAM role name (which is _not_ the same as the instance profile name)
+            if len(split_fields) == 3 and split_fields[0:2] == ['iam', 'security-credentials'] and ':' not in split_fields[2]:
+                new_fields[self._prefix % "iam-instance-profile-role"] = split_fields[2]
             if len(split_fields) > 1 and split_fields[1]:
                 new_key = "-".join(split_fields)
                 new_fields[self._prefix % new_key] = value
@@ -503,7 +504,7 @@ class Ec2Metadata(object):
                         dict = json.loads(content)
                         self._data['%s' % (new_uri)] = content
                         for (key, value) in dict.items():
-                            self._data['%s_%s' % (new_uri, key.lower())] = value
+                            self._data['%s:%s' % (new_uri, key.lower())] = value
                     except:
                         self._data['%s' % (new_uri)] = content  # not a stringifed JSON string