Add 'Account' textbox in Watcher UI for PagerDuty Action

[kapildawar]

Feature Request

Elasticsearch allows the setup of multiple accounts for Pagerduty notifications

xpack.notification.pagerduty:
  default_account: account2
  account:
    account1:
      ...
    account2:
      ...

The Watcher UI(threshold alert) for PagerDuty action does not have an option to put account for the watch being set up, it only has a textbox for description. Adding a textbox for Account will allow the user to indirectly select respective service API key and account defaults.
At this point, it requires an advanced watch to be set up for this.

Use case

Customers have multiple applications and application teams. PagerDuty allows setting up a service API key for every application team. This helps to route alerts to the corresponding team(email/slack) directly from PagerDuty. At this point, setting service_api_key or secure_service_api_key is under an account.

xpack.notification.pagerduty:
  account:
    my_pagerduty_account:
      service_api_key: d3b07384d113edec49eaa6238ad5ff0
      event_defaults:
        description: "Watch notification"
        incident_key: "my_incident_key"
        client: "my_client"
        client_url: http://www.example.org
        event_type: trigger
        attach_payload: true

Having an easy way to set account in watcher UI will help the user to set a threshold alert without having to write an advanced watcher.

[elasticmachine]

Pinging @elastic/es-ui (Team:Elasticsearch UI)