pixel-sepolicy: pixelstats: add /proc/vendor_mm/*

add /proc/vendor_mm/* for MM Metrics query.

Bug: 299190787
Test: local test: no related avc denied in dmesg and logcat logs

Change-Id: I1a11b7d07d4775f425179073eaa0cb274738188f
Signed-off-by: Robin Hsu <robinhsu@google.com>
3 files changed