Drop extra _system_file types.

They serve no purpose; these directories/files are normally accessible
in the same way as the rest of /system.  Also one of them has the wrong
attributes (data_file_type), thereby making it writable by some domains,
and under current policy, shell and apps cannot do ls -l /etc/ppp /etc/dhcpcd.

Change-Id: I0c1baa434fe78373684f4eaab40a41fddf2bdd79
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

dhcp.te

@@ -2,7 +2,6 @@ type dhcp, domain;
 permissive dhcp;
 type dhcp_exec, exec_type, file_type;
 type dhcp_data_file, file_type, data_file_type;
-type dhcp_system_file, file_type, data_file_type;
 
 init_daemon_domain(dhcp)
 net_domain(dhcp)
@@ -16,8 +15,6 @@ allow dhcp system_file:file rx_file_perms;
 # For /proc/sys/net/ipv4/conf/*/promote_secondaries
 allow dhcp proc_net:file write;
 allow dhcp system_prop:property_service set ;
-allow dhcp dhcp_system_file:file rx_file_perms;
-allow dhcp dhcp_system_file:dir r_dir_perms;
 unix_socket_connect(dhcp, property, init)
 allow dhcp owntty_device:chr_file rw_file_perms;
 

file_contexts

@@ -138,8 +138,6 @@
 /system/bin/pppd	u:object_r:ppp_exec:s0
 /system/bin/tf_daemon	u:object_r:tee_exec:s0
 /system/bin/racoon	u:object_r:racoon_exec:s0
-/system/etc/ppp(/.*)?	u:object_r:ppp_system_file:s0
-/system/etc/dhcpcd(/.*)? u:object_r:dhcp_system_file:s0
 /system/xbin/su		u:object_r:su_exec:s0
 /system/vendor/bin/gpsd u:object_r:gpsd_exec:s0
 /system/bin/dnsmasq     u:object_r:dnsmasq_exec:s0

ppp.te

@@ -2,6 +2,5 @@
 type ppp, domain;
 type ppp_device, dev_type;
 type ppp_exec, exec_type, file_type;
-type ppp_system_file, file_type;
 unconfined_domain(ppp)
 domain_auto_trans(mtp, ppp_exec, ppp)