ART: Make Touch's stack array smaller under ASAN

Under ASAN, especially on x86, there's a lot of overhead. To keep
below a single page, add a multiplier to the deduction.

Bug: 31098551
Bug: 62952017
Test: m
Test: SANITIZE_HOST=address SANITIZE_TARGET=address m ; manual assembly inspection
Change-Id: I8c80181e0fc5c6f4a1d3c6544f1a0e1089bb0631