Rename os-config-applier to os-apply-config

Since 1fde418207c004744dcc0d510bd88973ec05721a, os-config-applier is
deprecated. os-apply-config should be used instead.

Without this change, OS::Heat::SoftwareDeployment is broken because
the heat-config file is not created anymore in
/usr/libexec/os-apply-config/templates/var/run/heat-config.

Change-Id: I75d423f9fe15f2edaadba71174c4c20a3b2cd873