Allow netd to read the /dev/xt_qtaguid

After move qtaguid control interface into netd. Netd need to open the
xt_qtaguid resource tracking misc dev to make sure xt_qtaguid module is
successfully initialized before taking action. This selinux rule change
allows netd to do so and it is the same privilege normal apps currently
have.

Test: No more selinux denials on netd access qtaguid_device
Bug: 30950746
Change-Id: I79a98bbda3f3fdb85140a06a7532cdcc4354c518

public/netd.te

@@ -37,6 +37,8 @@ allow netd system_file:file lock;
 # TODO: Add proper rules to prevent other process to access qtaguid_proc file after migration
 #       complete
 allow netd qtaguid_proc:file rw_file_perms;
+# Allow netd to read /dev/qtaguid. This is the same privilege level that normal apps have.
+allow netd qtaguid_device:chr_file r_file_perms;
 
 r_dir_file(netd, proc_net)
 # For /proc/sys/net/ipv[46]/route/flush.