Rename security objects for accessing driver files.

Rename objects from shill_xxx to wifi_xxx.

Bug: 25154897
TEST=Manual test on dragonboard

Change-Id: Ib595090763210fb0e665f667a7bf7ad10fbfc7ef
diff --git a/peripheral/wifi/wcn3620/sepolicy/file_contexts b/peripheral/wifi/wcn3620/sepolicy/file_contexts
index f164b65..47a59e3 100644
--- a/peripheral/wifi/wcn3620/sepolicy/file_contexts
+++ b/peripheral/wifi/wcn3620/sepolicy/file_contexts
@@ -1,3 +1,3 @@
 # These files will be accessed by the HAL during wifi_init setup.
-/dev/wcnss_wlan            u:object_r:shill_device:s0
-/sys/devices/soc.0/a000000.qcom,wcnss-wlan/serial_number  u:object_r:shill_sysfs_entry:s0
+/dev/wcnss_wlan            u:object_r:wifi_device:s0
+/sys/devices/soc.0/a000000.qcom,wcnss-wlan/serial_number  u:object_r:wifi_sysfs_entry:s0