Allow sanitization of jemalloc.

Nosanitize was necessary to avoid linking sanitized jemalloc to libc,
which is a dependency of the asan runtime library, thus creating a
dependency loop. This is no longer a problem since libc is built with
soong which automatically suppresses sanitization as appropriate.

Bug: 33091541
Test: SANITIZE_TARGET=address keeps working

Change-Id: Ib15ab4daa4b0079a4fd77bea70cbc714005a9d39