Fix Deployment Approval popup to support Multiple approval rules

Summary

Users can't see the Deployment Approval popup in the Environment index/detail page when Multiple approval rules is configured.

Steps to reproduce

1. Configure Multiple approval rules
2. Try Approve or reject a deployment using the UI. You'll notice that there are no approval/reject buttons.

Example Project

What is the current bug behavior?

Can't do Approve or reject a deployment using the UI.

What is the expected correct behavior?

Can do Approve or reject a deployment using the UI.

The proper UI/UX changes for Multiple approval rules has already been issued in #355708 (closed) and #362236 (closed). These issues require UX consideration.

Relevant logs and/or screenshots

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

(For installations with omnibus-gitlab package run and paste the output of:
`sudo gitlab-rake gitlab:env:info`)

(For installations from source run and paste the output of:
`sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`)

Results of GitLab application Check

Expand for output related to the GitLab application check

(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:check SANITIZE=true)
(For installations from source run and paste the output of:
sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)
(we will only investigate if the tests are passing)

Possible fixes

See !87363 (closed) for the fix.