Merge "gn2bp: Add unwind related cflags to cflag_allowlist" am: 280adfaf75 am: 75adf1c99c

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2429636

Change-Id: I4f238c7959a7b2e7e787712616ca29f0f4d73fe1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>