build/base: don't install selinux-policy-default on Debian
build/base: don't install selinux-policy-default on Debian

Currently, SElinux in eDeploy images is only supported for Red Hat
deployments.
While some work is done to bring full Debian support, don't install the
package.
This patch could be reverted later if needed to re-enable again the
package.

redhat-cip/edeploy,lebauce/edeploy,redhat-cip/edeploy,enovance/edeploy,enovance/edeploy,lebauce/edeploy,enovance/edeploy,redhat-cip/edeploy,lebauce/edeploy,redhat-cip/edeploy,lebauce/edeploy,enovance/edeploy