[ALPS03982747] Add widevine sepolicy rules

Widevine provides a script in /vendor/widevine/
libwvdrmengine/move_widevine_data.sh that copies
the data files from /data to /data/vendor. Some
sepolicy rules are required to enable the device
to run this script.

MTK-Commit-Id: f7aba378699fc68e4e10ed2ed2b812c1e502e66f

Change-Id: I2731ad21da180a1a5f927c5631dcc579da1dc314
CR-Id: ALPS03982747
Feature: [Android Default] SELinux, SEAndroid, and SE-MTK