[aws] lambda_policy fix update when principal is an account number (#44871)

Fix KeyError on update when principal is an account number
(cherry picked from commit 1f3e7ea061)

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

@@ -236,7 +236,14 @@ def extract_statement(policy, sid):
     for statement in policy['Statement']:
         if statement['Sid'] == sid:
             policy_statement['action'] = statement['Action']
-            policy_statement['principal'] = statement['Principal']['Service']
+            try:
+                policy_statement['principal'] = statement['Principal']['Service']
+            except KeyError:
+                pass
+            try:
+                policy_statement['principal'] = statement['Principal']['AWS']
+            except KeyError:
+                pass
             try:
                 policy_statement['source_arn'] = statement['Condition']['ArnLike']['AWS:SourceArn']
             except KeyError: