Update apt keys

  * Add and switch apt.mirantis.com key

Related-Bug: PROD-17862 (PROD:17862)

Change-Id: I0cd21a3fb4d23a182660aa39643f885aa74852a3
diff --git a/linux/system/repo/mcp/apt_mirantis/extra.yml b/linux/system/repo/mcp/apt_mirantis/extra.yml
index 12e8adc..5523f55 100644
--- a/linux/system/repo/mcp/apt_mirantis/extra.yml
+++ b/linux/system/repo/mcp/apt_mirantis/extra.yml
@@ -10,6 +10,7 @@
       repo:
         mcp_extra:
           source: "deb ${_param:linux_system_repo_mcp_extra_url}/${_param:linux_system_codename} ${_param:linux_system_codename} main"
+          key: ${_param:linux_system_repo_mirror_mirantis_key}
           architectures: ${_param:linux_system_architecture}
           clean_file: true
           pin: