feat: script remove artifacts on android cd (close #15)

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

@@ -44,6 +44,12 @@ module Fastlane
           version_code: build_number
         )
 
+        # 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
+
         UI.success('🍺 Successfully build & deploy appbundle to Google Play Store')
       end