Update sms-voice models and endpoint tests to latest version. (boto#3553)

Author: aemous

.changes/next-release/api-change-pinpointsmsvoice-82194.json

@@ -0,0 +1,5 @@
+{
+  "type": "api-change",
+  "category": "``sms-voice``",
+  "description": "Updated the ``sms-voice`` client to the latest version. Note: this client is maintained only for backwards compatibility and should not be used for new development. We recommend using the ``pinpoint-sms-voice`` client for full support and ongoing updates."
+}