ANDROID: mm: vh for compaction begin/end

Add vendor hook for compaction begin/end.  The first use would be
to measure compaction durations.

Bug: 229927848
Test: echo 1 > /proc/sys/vm/compact_memory and observe output change in
/sys/kernel/pixel_stat/mm/compaction/mm_compaction_duration
Signed-off-by: Robin Hsu <robinhsu@google.com>
Change-Id: I3d95434bf49b37199056dc9ddfc36a59a7de17b7
Signed-off-by: Richard Chang <richardycc@google.com>
(cherry picked from commit 13b6bd38)
Signed-off-by: liangjlee <liangjlee@google.com>