Add bpttool to the trout source tree am: 37dda220a3

Original change: https://android-review.googlesource.com/c/device/google/trout/+/2322591

Change-Id: Id3d20ec56fa838632d9bbedfc9bb1500be625c8c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>