angler/sepolicy: Allow netmgrd to set net.r_rmnet* properties

Fix the following denials observed while setting gw and dns
proprties on r_rmnet* devices

init: sys_prop: permission denied uid:0 name:net.r_rmnet_data0.gw
init: avc:  denied  { set } for property=net.r_rmnet_data0.dns1
      scontext=u:r:netmgrd:s0 tcontext=u:object_r:system_prop:s0
      tclass=property_service
init: sys_prop: permission denied uid:0  name:net.r_rmnet_data0.dns1
init: avc:  denied  { set } for property=net.r_rmnet_data0.dns2
      scontext=u:r:netmgrd:s0 tcontext=u:object_r:system_prop:s0
      tclass=property_service
init: sys_prop: permission denied uid:0  name:net.r_rmnet_data0.dns2

Bug: 24837330

Change-Id: Ib10a3b8456b4de2bc26e110700b32f9caeed7f26
diff --git a/sepolicy/property_contexts b/sepolicy/property_contexts
index fa66e1d..a26c573 100644
--- a/sepolicy/property_contexts
+++ b/sepolicy/property_contexts
@@ -1,4 +1,5 @@
 ctl.ppd              u:object_r:ctl_ppd_prop:s0
 radio.atfwd.         u:object_r:radio_atfwd_prop:s0
 sensors.contexthub.  u:object_r:contexthub_prop:s0
-sys.ims.             u:object_r:qcom_ims_prop:s0
\ No newline at end of file
+sys.ims.             u:object_r:qcom_ims_prop:s0
+net.r_rmnet          u:object_r:net_radio_prop:s0