init: disable asan

Asan requires /proc to be mounted, which means it fundamentally cannot
be used with first stage init.  Given that second stage init now
contains the logic for first stage init, asan must be disabled on all
of init until this can be resolved.

Bug: 120424438
Bug: 120561310
Test: Asan builds boot
Change-Id: I24d1a0c8ecb5eb3f77435e6e36432c7b4cb97c6a