fix(rubocop): add fixes using `rubocop --safe-auto-correct`

test/integration/default/controls/config_spec.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Overide by OS
 keyfile = 'keyfile '
 driftfile = '/var/lib/chrony/'

test/integration/default/controls/packages_spec.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 control 'Chrony package' do
   title 'should be installed'
 

test/integration/default/controls/services_spec.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Overide by OS
 service_name =
   case os[:name]