ANDROID: vendor_hooks: Add hooks to avoid key threads stalled in

memory allocations

We add these hooks to avoid key threads blocked in memory allocation
path.
-android_vh_free_unref_page_bypass  ----We create a memory pool for the
key threads. This hook determines whether a page should be free to the
pool or to buddy freelist. It works with a existing hook
`android_vh_alloc_pages_reclaim_bypass`, which takes pages out of the
pool.

-android_vh_kvmalloc_node_use_vmalloc  ----For key threads, we perfer
not to run into direct reclaim. So we clear __GFP_DIRECT_RECLAIM flag.
For threads which are not that important, we perfer use vmalloc.

-android_vh_should_alloc_pages_retry  ----Before key threads run into
direct reclaim, we want to retry with a lower watermark.

-android_vh_unreserve_highatomic_bypass  ----We want to keep more
highatomic pages when unreserve them to avoid highatomic allocation
failures.

-android_vh_rmqueue_bulk_bypass  ----We found sometimes when key threads
run into rmqueue_bulk,  it took several milliseconds spinning at
zone->lock or filling per-cpu pages. We use this hook to take pages from
the mempool mentioned above,  rather than grab zone->lock and fill a
batch of pages to per-cpu.

Bug: 288216516
Change-Id: I1656032d6819ca627723341987b6094775bc345f
Signed-off-by: Oven <liyangouwen1@oppo.com>