change default direct method sender interval to 10s (Azure#4708)

Currently there is an issues with connectivity pipelines: Direct method call is failing while EdgeHub re-authenticating the module connected via MQTT protocol.
Increasing the duration to `10s` make the failure less frequent

test/modules/DirectMethodSender/config/appsettings.json

@@ -1,6 +1,6 @@
 {
     "EdgeHubConnectionString": "<YourConnectionString>",
     "TargetModuleId": "DirectMethodReceiver",
-    "DirectMethodDelay": "00:00:05",
+    "DirectMethodDelay": "00:00:10",
     "InvocationSource": "Local"
 }