Adjust Create issue button on the error tracking detail page for mobile

Summary

Create issue button on the error tracking detail page should take up full screen width on mobile viewports.

Steps to reproduce

1. Setup a project with sentry for error tracking
2. Go to the error tracking list page
3. Click on an error
4. Resize your window to a mobile viewport

Example Project

https://dev.gitlab.org/clement/error-tracking-test/-/error_tracking/1056573/details

What is the current bug behavior?

Create issue button is centered aligned, but does not take up the full width of the screen.

What is the expected correct behavior?

The current pattern observed within GitLab is to center the buttons on mobile viewports, and stretch them to fit the full width of the screen.

Example on the Pipelines page

Example on the Issues page

We should follow the same pattern here:

• Please refer to the breakpoints used on issues and pipelines page to determine when the button should scale to full width.
• Refer to the screenshot below for an example of the correct layout. The green "Create issue" button should be positioned the same way as the "Options" button in this screenshot on the small screen sizes.

Layout example

Relevant logs and/or screenshots

Output of checks

(If you are reporting a bug on GitLab.com, write: This bug happens on GitLab.com)

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

(If you can, link to the line of code that might be responsible for the problem)