Add GitLab host to 2FA QR and manual info

The two factor authentication account string only had the user's
email address. This led to ambiguous entries in two factor
code generating apps. This adds the GitLab host to the account
string in the standard format (according to Google). No matter
the code generator this change disambiguates the entry.

app/controllers/profiles/two_factor_auths_controller.rb

@@ -22,6 +22,7 @@ class Profiles::TwoFactorAuthsController < Profiles::ApplicationController
     end
 
     @qr_code = build_qr_code
+    @account_string = account_string
     setup_u2f_registration
   end
 
@@ -78,11 +79,14 @@ class Profiles::TwoFactorAuthsController < Profiles::ApplicationController
   private
 
   def build_qr_code
-    issuer = "#{issuer_host} | #{current_user.email}"
-    uri = current_user.otp_provisioning_uri(current_user.email, issuer: issuer)
+    uri = current_user.otp_provisioning_uri(account_string, issuer: issuer_host)
     RQRCode::render_qrcode(uri, :svg, level: :m, unit: 3)
   end
 
+  def account_string
+    "#{issuer_host}:#{current_user.email}"
+  end
+
   def issuer_host
     Gitlab.config.gitlab.host
   end

app/views/profiles/two_factor_auths/show.html.haml

@@ -30,7 +30,7 @@
               To add the entry manually, provide the following details to the application on your phone.
             %p.prepend-top-0.append-bottom-0
               Account:
-              = current_user.email
+              = @account_string
             %p.prepend-top-0.append-bottom-0
               Key:
               = current_user.otp_secret.scan(/.{4}/).join(' ')

changelogs/unreleased/add_info_to_qr.yml

+---
+title: Add GitLab host to 2FA QR code and manual info
+merge_request: 6941
+author: