No need for #pragma once in bindgen header. am: 1ae7385469

Original change: https://android-review.googlesource.com/c/platform/system/librustutils/+/2584505

Change-Id: I808db7adddc7ab54c855dd80f206a91f4ab3f471
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>