tree d6e11a3aea79094f774ec11b2b6b8e899e6f0614
parent dc282ead05da82a1851d2bcb2ecfd0ec44e35c10
author Nan Zhang <nanzhang@google.com> 1519161087 -0800
committer Nan Zhang <nanzhang@google.com> 1519237752 -0800

Use HAS_BUILD_NUMBER to check engineering build

And use BUILD_NUMBER_FROM_FILE instead of BUILD_NUMBER to reduce build
reruns.

Test: m -j32
Bug: b/70351683
Change-Id: Ic2a6e2095712828c8314fdd5fca7669f2fb88bc3