ANDROID: task_mmu: add vendor hook to show swap_shared

Add vendor hook to show swap_shared for more information of a process.
This commit will be merged in future kernel with below commit.
https://android-review.googlesource.com/c/kernel/common/+/3064567



Bug: 351175506
Change-Id: I49173439e4c8af208f829758e358f1e97e1ff4ff
Signed-off-by: Sooyong Suk <s.suk@samsung.corp-partner.google.com>