Revert "Disable ubsan diagnostics under HWASan."

The original problem has been fixed in LLVM:
https://reviews.llvm.org/rG78f7e6d8d7956cb96d0fa0fd606192ca0218eee1

Bug: 191808836
Bug: 209991446
Test: m net_test_btm_iso with SANITIZE_TARGET=hwaddress

This reverts commit b15a5648.

Change-Id: Ie99a9a204e0a3f7c3ddf3efd74ac7f19db90215a