Switch to libunwind to remove dependency on libgcc for musl am: 441898c2 am:...

Switch to libunwind to remove dependency on libgcc for musl am: 441898c2 am: b7ea2f5c am: d1b5f338 am: a1523563

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/1983628



Change-Id: I704668c3463d6f6d42239a8b65d437a6add2c915
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>