ANDROID: add vendor fields to swap_info_struct to record swap stats

struct swap_info_struct :: ANDROID_VENDOR_DATA(1)
	It is pointer to a struct to record the following message:
	1) total swapin pages;
	2) total swapout pages;
	3) total number of cold pages swapin;
	4) total number of swapout pages, specified by userspace;
	5) total number of swapout pages, specified by kernel;
	6) the maxmium number of swapout pages;
	7) the maxmium number of swapout pages allowed by kernel;
	8) the maxmium number of swapout pages allowed by framework;

Bug: 225795494
Change-Id: I779145a83d87e339db86ec81c7f962be99946afb
Signed-off-by: Bing Han <bing.han@transsion.com>
(cherry picked from commit af4eb0e3)
(cherry picked from commit 29277e2b)