Don't leak constants in stub feature flag spec

spec/support_specs/helpers/stub_feature_flags_spec.rb

@@ -3,7 +3,7 @@
 require 'spec_helper'
 
 RSpec.describe StubFeatureFlags do
-  DUMMY_FEATURE_FLAG = :dummy_feature_flag # rubocop:disable RSpec/LeakyConstantDeclaration
+  let_it_be(:dummy_feature_flag) { :dummy_feature_flag }
 
   # We inject dummy feature flag defintion
   # to ensure that we strong validate it's usage
@@ -11,23 +11,23 @@ RSpec.describe StubFeatureFlags do
   before(:all) do
     definition = Feature::Definition.new(
       nil,
-      name: DUMMY_FEATURE_FLAG,
+      name: dummy_feature_flag,
       type: 'development',
       # we allow ambigious usage of `default_enabled:`
       default_enabled: [false, true]
     )
 
-    Feature::Definition.definitions[DUMMY_FEATURE_FLAG] = definition
+    Feature::Definition.definitions[dummy_feature_flag] = definition
   end
 
   after(:all) do
-    Feature::Definition.definitions.delete(DUMMY_FEATURE_FLAG)
+    Feature::Definition.definitions.delete(dummy_feature_flag)
   end
 
   describe '#stub_feature_flags' do
     using RSpec::Parameterized::TableSyntax
 
-    let(:feature_name) { DUMMY_FEATURE_FLAG }
+    let(:feature_name) { dummy_feature_flag }
 
     context 'when checking global state' do
       where(:feature_actors, :expected_result) do
@@ -140,14 +140,14 @@ RSpec.describe StubFeatureFlags do
 
   describe 'stub timing' do
     context 'let_it_be variable' do
-      let_it_be(:let_it_be_var) { Feature.enabled?(DUMMY_FEATURE_FLAG) }
+      let_it_be(:let_it_be_var) { Feature.enabled?(dummy_feature_flag) }
 
       it { expect(let_it_be_var).to eq true }
     end
 
     context 'before_all variable' do
       before_all do
-        @suite_var = Feature.enabled?(DUMMY_FEATURE_FLAG)
+        @suite_var = Feature.enabled?(dummy_feature_flag)
       end
 
       it { expect(@suite_var).to eq true }
@@ -155,14 +155,14 @@ RSpec.describe StubFeatureFlags do
 
     context 'before(:all) variable' do
       before(:all) do
-        @suite_var = Feature.enabled?(DUMMY_FEATURE_FLAG)
+        @suite_var = Feature.enabled?(dummy_feature_flag)
       end
 
       it { expect(@suite_var).to eq true }
     end
 
     context 'with stub_feature_flags meta' do
-      let(:var) { Feature.enabled?(DUMMY_FEATURE_FLAG) }
+      let(:var) { Feature.enabled?(dummy_feature_flag) }
 
       context 'as true', :stub_feature_flags do
         it { expect(var).to eq true }