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/vendor_init.te b/private/vendor_init.te
index 6a68f1f..83f001d 100644
--- a/private/vendor_init.te
+++ b/private/vendor_init.te
@@ -5,3 +5,6 @@
 
 # TODO(b/140259336) We want to remove vendor_init in the long term but allow for now
 allow vendor_init system_data_root_file:dir rw_dir_perms;
+
+# Let vendor_init set service.adb.tcp.port.
+set_prop(vendor_init, adbd_config_prop)