Merge "fastboot: Add header that declares std::function" am: 1f876a81dd

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2620235

Change-Id: Ie2454f2d45b6cba525dc0b65176e6f154149e2ec
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>