Remove libchrome stringprintf.h functions am: 11c3da63da

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/3316555

Change-Id: Iaf798764ab7bb4bb068bfb90656158d0bbec7f67
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>