[automerger skipped] Add global C flags to compile_commands am: b763553ed3 -s ours

am skip reason: Merged-In Id583da6eb5151a9baa9a47771f5f937c88bc43f7 with SHA-1 342fa6b927 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/soong/+/26769180

Change-Id: I2a557710a811c535ca5ffa461dded64b7946613a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>