Allow vendor_init to set service.adb.tcp.port

adbd and apps (SystemUI and CTS test apps) need to read it.

BUG: 162205386
Test: Connect to device which sets service.adb.tcp.port in vendor
      partition through TCP adb.

Change-Id: Ia37dd0dd3239381feb2a4484179a0c7847166b29
diff --git a/private/app.te b/private/app.te
index 5b079c2..21a6b82 100644
--- a/private/app.te
+++ b/private/app.te
@@ -11,6 +11,7 @@
 get_prop(appdomain, telephony_config_prop)
 get_prop(appdomain, userspace_reboot_config_prop)
 get_prop(appdomain, vold_config_prop)
+get_prop(appdomain, adbd_config_prop)
 
 userdebug_or_eng(`perfetto_producer({ appdomain })')