ANDROID: vendor_hooks: add hooks for exting task's swp_entrys

The process exit time is mainly caused by freeing its swp_entrys. When
low memory triggers to kill lots of processes exit simultaneously, there
is a problem of CPU high load occupied by the exiting processes.

This feature is used to asynchronously maintain and release the
swp_entrys of the exiting process to accelerate the efficiency of the
exiting process.

Bug: 364480846
Bug: 340798358
Change-Id: I6fc0b813e7ac6a0796e08ce7a17d5ff3ab2b799b
Signed-off-by: Justin Jiang <justinjiang@vivo.corp-partner.google.com>