Fixes two broken links for SSM scenarios. (#6855)

Author: beqqrry-aws

.doc_gen/metadata/ssm_metadata.yaml

@@ -32,7 +32,7 @@ ssm_Hello:
               snippet_tags:
                 - python.example_code.ssm.Hello
   services:
-    ssm: {listThings}
+    ssm: {ListDocuments}
 ssm_DescribeParameters:
   languages:
     Java:
@@ -456,5 +456,5 @@ ssm_Scenario:
               snippet_tags:
                 - python.example_code.ssm.MaintenanceWindowWrapper.class
   services:
-    ssm: {CreateOpsItem, CreateMaintenanceWindow, CreateDocument, SendCommand, CommandInvocations, DeleteMaintenanceWindow,
+    ssm: {CreateOpsItem, CreateMaintenanceWindow, CreateDocument, SendCommand, ListCommandInvocations, DeleteMaintenanceWindow,
           UpdateOpsItem}

javascriptv3/example_code/ssm/README.md

@@ -31,7 +31,7 @@ For prerequisites, see the [README](../../README.md#Prerequisites) in the `javas
 
 ### Get started
 
-- [Hello Systems Manager](hello.js#L4) (`listThings`)
+- [Hello Systems Manager](hello.js#L4) (`ListDocuments`)
 
 
 ### Basics

javav2/example_code/ssm/README.md

@@ -31,7 +31,7 @@ For prerequisites, see the [README](../../README.md#Prerequisites) in the `javav
 
 ### Get started
 
-- [Hello Systems Manager](src/main/java/com/example/ssm/HelloSSM.java#L6) (`listThings`)
+- [Hello Systems Manager](src/main/java/com/example/ssm/HelloSSM.java#L6) (`ListDocuments`)
 
 
 ### Basics

python/example_code/ssm/README.md

@@ -36,7 +36,7 @@ python -m pip install -r requirements.txt
 
 ### Get started
 
-- [Hello Systems Manager](hello.py#L4) (`listThings`)
+- [Hello Systems Manager](hello.py#L4) (`ListDocuments`)
 
 
 ### Basics