Remove domain_deprecated from mdnsd. This removes some unnecessarily
permissive rules from mdnsd.

As part of this, re-allow /proc/net access, which is removed as
a result of removing domain_deprecated.

Bug: 25433265
Change-Id: Ie1cf27179ac2e9170cf4cd418aea3256b9534603

Motivation: Domain is overly permissive. Start removing permissions
from domain and assign them to the domain_deprecated attribute.
Domain_deprecated and domain can initially be assigned to all
domains. The goal is to not assign domain_deprecated to new domains
and to start removing domain_deprecated where it is not required or
reassigning the appropriate permissions to the inheriting domain
when necessary.

Bug: 25433265
Change-Id: I8b11cb137df7bdd382629c98d916a73fe276413c

When using MLS (i.e. enabling levelFrom= in seapp_contexts),
certain domains and types must be exempted from the normal
constraints defined in the mls file.  Beyond the current
set, adbd, logd, mdnsd, netd, and servicemanager need to
be able to read/write to any level in order to communicate
with apps running with any level, and the logdr and logdw
sockets need to be writable by apps running with any level.

This change has no impact unless levelFrom= is specified in
seapp_contexts, so by itself it is a no-op.

Change-Id: I36ed382b04a60a472e245a77055db294d3e708c3
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

Change-Id: I610723eb9f2edcb4525b0e2d7e55616a1d93957d
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

(cherry picked from commit 96ff4c05)

Change-Id: Idfd734f07687925c1f35d2629d4b59d46822d0d4

Change-Id: I0a06fa32a46e515671b4e9a6f68e1a3f8b2c21a8
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>