ANDROID: freezer: Add vendor hook to freezer for GKI purpose.

Add the vendor hook to freezer.c so that OEM's logic can be executed
when the process is about to be frozen. We need to clear the flag for
some tasks and rebind task dependencies for optimization purposes.

Bug: 339371220
Bug: 187458531
Bug: 281920779

Signed-off-by: heshuai1 <heshuai1@xiaomi.com>
Change-Id: Iea42fd9604d6b33ccd6502425416f0dd28eecebb
(cherry picked from commit a1580311)