ci: upgrade builds to use Bazel 1.0 (#1004)

Now that Bazel reached 1.0 and it is expected to follow semver, it seems
better to test with that version. The downside is that we may not notice
breakage for users in the 0.28.0-0.29.0 range. But it seems that Bazel
users are rapidly moving towards using 1.0 anyway.

Apparently Bazel-1.0 cannot build gRPC with Clang-3.8 on Ubuntu-16.04. I
am not sure which of those version numbers is the critical one, but
don't care. The goal is to test our code with Clang-3.8, so using Bazel
or CMake does not matter to us.

Author: coryan

ci/install-bazel.sh

@@ -18,7 +18,7 @@ set -eu
 readonly PLATFORM=$(printf "%s-%s" "$(uname -s)" "$(uname -m)" \
   |  tr '[:upper:]' '[:lower:]')
 
-readonly BAZEL_VERSION="0.28.0"
+readonly BAZEL_VERSION="1.0.0"
 readonly GITHUB_DL="https://github.com/bazelbuild/bazel/releases/download"
 readonly SCRIPT_NAME="bazel-${BAZEL_VERSION}-installer-${PLATFORM}.sh"
 wget -q "${GITHUB_DL}/${BAZEL_VERSION}/${SCRIPT_NAME}"

ci/kokoro/docker/build.sh

@@ -152,6 +152,8 @@ elif [[ "${BUILD_NAME}" = "clang-3.8" ]]; then
   export DISTRO_VERSION=16.04
   export CC=clang
   export CXX=clang++
+  export CMAKE_SOURCE_DIR="super"
+  in_docker_script="ci/kokoro/docker/build-in-docker-cmake.sh"
 elif [[ "${BUILD_NAME}" = "cxx17" ]]; then
   export GOOGLE_CLOUD_CPP_CXX_STANDARD=17
   export DISTRO=fedora-install