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>
diff --git a/pixelstats/file.te b/pixelstats/file.te
index 76f87a2..b8de8a5 100644
--- a/pixelstats/file.te
+++ b/pixelstats/file.te
@@ -1,2 +1,3 @@
 type debugfs_mgm, debugfs_type, fs_type;
 type sysfs_pixel_stat, fs_type, sysfs_type;
+type proc_vendor_mm, fs_type, proc_type;