Enable frozen string for spec/policies

Partially addresses:

https://gitlab.com/gitlab-org/gitlab/issues/27703

spec/policies/application_setting/term_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe ApplicationSetting::TermPolicy do

spec/policies/base_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe BasePolicy do

spec/policies/ci/build_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Ci::BuildPolicy do

spec/policies/ci/pipeline_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Ci::PipelinePolicy, :models do

spec/policies/ci/pipeline_schedule_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Ci::PipelineSchedulePolicy, :models do

spec/policies/ci/trigger_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Ci::TriggerPolicy do

spec/policies/clusters/cluster_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Clusters::ClusterPolicy, :models do

spec/policies/deploy_key_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe DeployKeyPolicy do

spec/policies/deploy_token_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe DeployTokenPolicy do

spec/policies/environment_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe EnvironmentPolicy do

spec/policies/global_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe GlobalPolicy do

spec/policies/group_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe GroupPolicy do

spec/policies/issuable_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe IssuablePolicy, models: true do

spec/policies/issue_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe IssuePolicy do

spec/policies/merge_request_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe MergeRequestPolicy do

spec/policies/namespace_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe NamespacePolicy do

spec/policies/note_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe NotePolicy do

spec/policies/personal_snippet_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 # Snippet visibility scenarios are included in more details in spec/support/snippet_visibility.rb

spec/policies/project_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe ProjectPolicy do

spec/policies/project_snippet_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 # Snippet visibility scenarios are included in more details in spec/support/snippet_visibility.rb

spec/policies/protected_branch_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe ProtectedBranchPolicy do

spec/policies/resource_label_event_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe ResourceLabelEventPolicy do

spec/policies/user_policy_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe UserPolicy do