netmgrd: give explicit read access to /proc/net
netmgrd: give explicit read access to /proc/net

We plan to remove /proc/net access from domain.te in a future
change. Make sure netmgrd doesn't depend on the rules in domain.te.

Bug: 9496886
Change-Id: I0f167f1e758f48d0bf0f0e54cd7154663295484b

maruos/android_device_lge_hammerhead,maruos/android_device_lge_hammerhead,maruos/android_device_lge_hammerhead,maruos/android_device_lge_hammerhead