sm8350-common: ueventd: Don't modify permissions of /dev/hw_random

This addresses an underlying problem since /dev/hw_random is used. The
issue is that EntropyMixer, which runs in system_server, needs to read
from /dev/hw_random, but thanks to our qualcomm ueventd, EntropyMixer
can never accress this node, resulting in warnings like this:

W EntropyMixer: Failed to add HW RNG output to entropy pool
W EntropyMixer: java.io.FileNotFoundException: /dev/hw_random (Permission denied)

AOSP ueventd handles this well, so just remove this line to get things
back to stage. This issue was never exposed because Google derps the
logging here, which is already fixed on Pie.

https://android.googlesource.com/platform/frameworks/base/+/c78a463e875d91eae2cf256042fd99d130217c38

Change-Id: I42c9aaa8f57306536e51c0a17febad57a5a77581