Support max_byte_size settings for instance SAML

We had saml_message_max_byte_size settings which was only applicable for
group SAML. This MR enables the instance same config to configure
maximum message size

Changelog: fixed

config/initializers/1_settings.rb

@@ -160,6 +160,10 @@
     end
 end
 
+# Fill out default Settings for omniauth-saml
+
+OmniAuth::Strategies::SAML.default_options['message_max_bytesize'] = Settings.omniauth['saml_message_max_byte_size']
+
 # SAML should be enabled for the tests automatically, but only for EE.
 saml_provider_enabled = Settings.omniauth.providers.any? do |provider|
   provider['name'] == 'group_saml'

scripts/setup-test-env

@@ -24,6 +24,7 @@ require_relative '../lib/system_check/helpers'
 # Required for config/initializers/1_settings.rb
 require 'omniauth'
 require 'omniauth-github'
+require 'omniauth-saml'
 require 'etc'
 require 'gitlab/utils/all'
 require 'gitlab/safe_request_store'