Add default variable for ubuntu repos

  * Fix keystorage classes include

Change-Id: I2eb60bc1b828f797c1a118b3ca08e20da7fe66e0
diff --git a/linux/system/repo/mcp/apt_mirantis/ubuntu.yml b/linux/system/repo/mcp/apt_mirantis/ubuntu.yml
index 472dc63..55f6387 100644
--- a/linux/system/repo/mcp/apt_mirantis/ubuntu.yml
+++ b/linux/system/repo/mcp/apt_mirantis/ubuntu.yml
@@ -1,8 +1,9 @@
 classes:
-- system.repo.keystorage.ubuntu
+- system.linux.system.repo.keystorage.ubuntu
 parameters:
   _param:
     apt_mk_version: 'stable'
+    linux_repo_refresh_db: true
     linux_system_repo_url: http://mirror.mirantis.com/${_param:apt_mk_version}/
     linux_system_repo_ubuntu_url: ${_param:linux_system_repo_url}/ubuntu/
   linux: