Update Grafana Slack Channel
UpdateAGrafanaSlackNotificationChannel[PUT]    
curl -X PUT https://accelerator.shimmercat.com/presentation-api/v1/grafana-notification-channel/slack/<channel_id> -H 'Authorization: Token <your_authentication_token>' -H 'Content-type: application/json' -d '{"grafana_uid": "<user-id>", "slack_channel_name": "<channel-name>", "slack_hook_url": "<www.example.com>"}'
curl -X PUT https://accelerator.shimmercat.com/presentation-api/v1/grafana-notification-channel/slack/<channel_id> -H 'Authorization: Token <your_authentication_token>' -H 'Content-type: application/json' -d '{"grafana_uid": "<user-id>", "slack_channel_name": "<channel-name>", "slack_hook_url": "<www.example.com>"}'
Update a single Grafana Slack Notification Channel.