[Rails5] Fix project's path check

What does this MR do?

When importing a project, after clicking 'Create Project' button, user is redirected either to to the project's import page or project's show page depending whether import is still in progress.

In Rails 5, the test is failing because user is still on project_import_path (in opposite to rails 4 where user is already on the project's show page), this difference is probably because test_after_commit is now included in rails 5 by default (see https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/6771#note_94358949). This MR updates the failing spec to accept project's import page in rails 5.

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Conforms to the code review guidelines
  • Has been reviewed by a UX Designer
  • Has been reviewed by a Frontend maintainer
  • Has been reviewed by a Backend maintainer
  • Has been reviewed by a Database specialist
• EE specific content should be in the top level /ee folder
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• If you have multiple commits, please combine them into a few logically organized commits by squashing them
• Internationalization required/considered
• If paid feature, have we considered GitLab.com plan and how it works for groups and is there a design for promoting it to users who aren't on the correct plan
• End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?

Closes #7081 (closed)