Remove unlabeled execute access from domain, add to appdomain.

Otherwise all domains can create/write files that are executable
by all other domains.  If I understand correctly, this should
only be necessary for app domains executing content from legacy
unlabeled userdata partitions on existing devices and zygote
and system_server mappings of dalvikcache files, so only allow
it for those domains.

If required for others, add it to the individual
domain .te file, not for all domains.

Change-Id: I6f5715eb1ecf2911e70772b9ab4e531feea18819
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
diff --git a/system_server.te b/system_server.te
index 37d4cc6..22d739b 100644
--- a/system_server.te
+++ b/system_server.te
@@ -239,3 +239,8 @@
 
 # For SELinuxPolicyInstallReceiver
 selinux_manage_policy(system_server)
+
+# For legacy unlabeled userdata on existing devices.
+# See discussion of Unlabeled files in domain.te for more information.
+# This rule is for dalvikcache mmap/mprotect PROT_EXEC.
+allow system_server unlabeled:file execute;