In some upgrade scenarios, Ambari Web's persist key-value store state causes the UI to act unpredictably

During Ambari upgrade, automatically clear the persist state to prevent potential issues with Ambari Web not working properly (this was observed a number of times on upgraded clusters).

Currently, we make the following call to get out of the inconsistent state so that Ambari Web works properly:

curl -i -u admin:admin -H "X-Requested-By: ambari" -X POST -d '{ "CLUSTER_CURRENT_STATUS": "{\"clusterState\":\"CLUSTER_STARTED_5\"}" }' http://localhost:8080/api/v1/persist

We need to do something equivalent during upgrade.