The previous commit 5da38f60a2 is not
complete since `GetArt(true)` will destroy the static SandHook::ElfImg
object.
Since in the previous two commits we have postponed the initialization
of LSPlant, we can now keep the symbol cache of `libart` for the
InitArtHooker call in method `OnNativeForkSystemServerPost`. Symbol
cache works because we are using local static object in the function
`GetArt`, whose life-cycle is not constraint by the function block.