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

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

Change-Id: I71ff341318a840488d81046d15c3764db7d259ab
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>