When creating the Slack integration, it became active after access to Slack workspace is "Allowed" but before first saving the integration.

Issue Summary

When creating the Slack integration, the user is guided to login to their Slack workspace and to select a channel.  As soon as the "Allow" button is clicked, but before the "Save Integration", the integration is added and already active with the default "Match all alerts" and all "Alert Action" configured. 

In one such case, the customer flooded his Slack channel with alert notifications before he could set the desired Alert Filter conditions and Alert Actions.

Steps to Reproduce

1. Add a new Slack integration and follow the prompt to Allow access to the Slack workspace 
2. Do not click "Save Integration"

Expected Results

When the integration is not yet saved, one would expect that the integration is not yet active.

Actual Results

The Slack integration is already active and able to send messages to the selected Slack channel

Workaround

The workaround would be to create the slack integration within a "dormant" Team, i.e. one that doesn't have members or that doesn't get alerts.  Then set the desired filters conditions and alert actions before assigning the integration to the desired team.  This workaround can be done by the global Opsgenie Admin or by the user with Team Admin access to both the "dormant" team and their own team.