[gwp_asan] Use __sanitizer_fast_backtrace on Fuchsia am: e2919d1a60

Original change: https://android-review.googlesource.com/c/platform/external/gwp_asan/+/1703586

Change-Id: Ic98cbcc02e6aaa6c7d98a92cb2a8a3c7d297ff5b