Fix apparmor to allow for new cert scheme.

This sets the abstraction/ssl_certs profile to allow
/etc/ssl/localcerts; the file is taken from Trusty but is
compatible with previous releases.  There is a guard
in the manifest to cause a failiure in the presence of
future releases so that the profile can be revalidated.

Change-Id: I491e27fe1056cbc1e3f6a42921cef4624cf98253