Let adbd set service.adb.tcp.port.

Commit 67c36884 changed the label of service.adb.tcp.port to allow
vendor init to set it, but accidentally prevented adbd from setting it,
which broke `adb tcpip`.

Bug: http://b/171280882
Test: `adb tcpip`
Change-Id: I154e2f43a4d3b72b27508ce02d66298673939738
diff --git a/private/property.te b/private/property.te
index bf73c3d..53f4284 100644
--- a/private/property.te
+++ b/private/property.te
@@ -322,6 +322,16 @@
   system_adbd_prop
 }:property_service set;
 
+# Let (vendor_)init, adbd, and system_server set service.adb.tcp.port
+neverallow {
+  -init
+  -vendor_init
+  -adbd
+  -system_server
+} {
+  adbd_config_prop
+}:property_service set;
+
 neverallow {
   # Only allow init and adbd to set adbd_prop
   -init