Add slack webhook

Author: mdotb-moz

.github/workflows/fireoxos-ios-testrail-milestone.yml

@@ -15,11 +15,13 @@ jobs:
           echo "Tag: ${{ github.event.release.tag_name }}"
           echo "Release Name: ${{ github.event.release.name }}"
           echo "Body: ${{ github.event.release.body }}"
+          echo "Slack Webhook Url: ${{ secrets.SLACK_MOBILE_ALERTS_SANDBOX_CHANNEL }}"
       - name: Run the reusable action from branch
         uses: mozilla-mobile/testops-tools/.github/actions/firefox-ios-milestone@mb/firefox-ios-milestone
         with:
           release-name: ${{ github.event.release.name }}
           release-tag: ${{ github.event.release.tag_name }}
           testrail-host: ${{ secrets.TESTRAIL_HOST }}
           testrail-username: ${{ secrets.TESTRAIL_USERNAME }}
-          testrail-api-key: ${{ secrets.TESTRAIL_PASSWORD }}
+          testrail-api-key: ${{ secrets.TESTRAIL_PASSWORD }}
+          slack_webhook_url: ${{ secrets.SLACK_MOBILE_ALERTS_SANDBOX_CHANNEL }}