Rename legacy validation helpers for new ci config

lib/ci/gitlab_ci_yaml_processor.rb

@@ -2,7 +2,7 @@ module Ci
   class GitlabCiYamlProcessor
     class ValidationError < StandardError; end
-    include Gitlab::Ci::Config::Node::ValidationHelpers
+    include Gitlab::Ci::Config::Node::LegacyValidationHelpers
     DEFAULT_STAGES = %w(build test deploy)
     DEFAULT_STAGE = 'test'

lib/gitlab/ci/config/node/validation_helpers.rb → lib/gitlab/ci/config/node/legacy_validation_helpers.rb

@@ -2,7 +2,7 @@ module Gitlab
   module Ci
     class Config
       module Node
-        module ValidationHelpers
+        module LegacyValidationHelpers
           private
           def validate_duration(value)

lib/gitlab/ci/config/node/script.rb

@@ -14,7 +14,7 @@ module Gitlab
           include Validatable
           validations do
-            include ValidationHelpers
+            include LegacyValidationHelpers
             validate :array_of_strings