SEAndroid: Enable rild_oem socket policies for radio

Adding required SEAndroid policies to enable rild_oem socket connection
from QcrilMsgTunnel app (radio UID group) as it is currently denied
by SEAndroid module.

Change-Id: Ie1a1d2fdd0fe85095d8e33c8c6d5d335c3dc2042

Android.mk

@@ -15,6 +15,7 @@ BOARD_SEPOLICY_UNION := \
        qmuxd.te \
        netmgrd.te \
        atfwd.te \
+       radio.te \
        smd_test.te \
        qmi_ping.te \
        qmi_test_service.te \

radio.te

@@ -0,0 +1,3 @@
+# Talks to qmuxd via the qmux_radio socket.
+unix_socket_connect(radio, qmux_radio, qmuxd);
+allow radio qmux_radio_socket:dir search;