Revert "ANDROID: vendor_hooks: tune reclaim scan type for specified mem_cgroup"

This reverts commit e5b4949b.

The hook android_vh_tune_memcg_scan_type is not used by any vendor, so
remove it to help with merge issues with future LTS releases.

If this is needed by any real user, it can easily be reverted to add it
back and then the symbol should be added to the abi list at the same
time to prevent it from being removed again later.

Bug: 203756332
Bug: 230450931
Cc: xiaofeng <xiaofeng5@xiaomi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I0e32c24d67a9ede087eca5005796512a9451c1e2