Merge "host_signal_fixup.h: remove unused file." into main am: c9d70be7fe

Original change: https://android-review.googlesource.com/c/platform/system/core/+/3241480

Change-Id: I226ee2972e0467eb9abfbc62440e17028f5eee11
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>