Merge branch 'stable-2.16' into stable-3.0 * stable-2.16: Bump bazel version to 1.0.0 Add PolyGerrit UI for configuring uploadvalidator Upgrade bazlets to latest stable-2.16 to build with 2.16.12 API Upgrade bazlets to latest stable-2.15 to build with 2.15.17 API Change-Id: I40633e357b1fe9c579ede32a1039042830c1f612