sepolicy(hal_wifi): Allow wifi HAL to access persist.vendor.debug properties

We want to tweak some device params at runtime via shell (alleviates the
need to recompile HAL for changing device configuration). This will help
us test/teamfood couple of new features under development.

Bug: 173044646
Test: Wifi HAL can read persist.vendor.debug.wifi properties.
Change-Id: Iabd07e72aa5f0d97519a37d0ebb1e0a3458b6d06
diff --git a/public/hal_wifi.te b/public/hal_wifi.te
index fddfda1..ef831a1 100644
--- a/public/hal_wifi.te
+++ b/public/hal_wifi.te
@@ -9,6 +9,7 @@
 
 set_prop(hal_wifi, wifi_hal_prop)
 set_prop(hal_wifi, wifi_prop)
+userdebug_or_eng(`get_prop(hal_wifi, persist_vendor_debug_wifi_prop)')
 
 # allow hal wifi set interfaces up and down and get the factory MAC
 allow hal_wifi self:udp_socket create_socket_perms;