refactor: move delete artifacts fn in helper for android lane

plugins/fastlane-plugin-android_cd/lib/fastlane/plugin/android_cd/actions/build_and_deploy_action.rb

@@ -50,9 +50,7 @@ module Fastlane
 
         # Delete artifacts files
         artifacts = ['android_keys.zip', 'key.jks', 'key.properties', 'service_account_key.json']
-        artifacts.each do |file|
-          File.delete(file) if File.exist?(file)
-        end
+        Helper::AndroidCdHelper.delete_artifacts(artifacts)
 
         UI.success('🍺 Successfully build & deploy appbundle to Google Play Store')
       end

plugins/fastlane-plugin-android_cd/lib/fastlane/plugin/android_cd/helper/android_cd_helper.rb

@@ -26,6 +26,13 @@ module Fastlane
         str_variable = variable.strip if variable.class.to_s == "String"
         variable && !(str_variable.nil? || str_variable.empty?)
       end
+
+      # Delete built files
+      def self.delete_artifacts(artifacts)
+        artifacts.each do |file|
+          File.delete(file) if File.exist?(file)
+        end
+      end
     end
   end
 end