Merge "Switch mkbootfs to C++." into main am: 95de81f71f am: 4b6c837962

Original change: https://android-review.googlesource.com/c/platform/system/core/+/3323749

Change-Id: Ic0ba8143193c2d5d88c466aa6db9c6569cce27ef
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>