Merge branch 'ee-ee-183-common-code-backport' into 'master'

Port of ee-183-common-code-backport to EE

See merge request gitlab-org/gitlab-ee!4860

lib/gitlab/utils.rb

@@ -68,6 +68,14 @@ module Gitlab
       nil
     end
 
+    # Used in EE
+    # Accepts either an Array or a String and returns an array
+    def ensure_array_from_string(string_or_array)
+      return string_or_array if string_or_array.is_a?(Array)
+
+      string_or_array.split(',').map(&:strip)
+    end
+
     # EE below
     def try_megabytes_to_bytes(size)
       Integer(size).megabytes