[libcxxabi] __cxa_guard_require: test guard byte with != 0 instead of == 1 am: 6f1796448f am: bda6af8573 am: 29d50b4282

Original change: https://android-review.googlesource.com/c/platform/external/libcxxabi/+/1727437

Change-Id: Ic9caa4873a69d6482a559f05a294fe2e9cac2369