upgrade bazel to 0.23.2 for docker legacy bazel builds

excluded Python tests from Bazel legacy C/C++ Kokoro CI jobs
disabled building examples due to existance of python

templates/tools/dockerfile/bazel.include

@@ -2,6 +2,6 @@
 # Bazel installation
 
 RUN apt-get update && apt-get install -y wget && apt-get clean
-RUN wget https://github.com/bazelbuild/bazel/releases/download/0.20.0/bazel-0.20.0-installer-linux-x86_64.sh && ${'\\'}
-  bash ./bazel-0.20.0-installer-linux-x86_64.sh && ${'\\'}
-  rm bazel-0.20.0-installer-linux-x86_64.sh
+RUN wget https://github.com/bazelbuild/bazel/releases/download/0.23.2/bazel-0.23.2-installer-linux-x86_64.sh && ${'\\'}
+  bash ./bazel-0.23.2-installer-linux-x86_64.sh && ${'\\'}
+  rm bazel-0.23.2-installer-linux-x86_64.sh

tools/dockerfile/test/bazel/Dockerfile

@@ -52,9 +52,9 @@ RUN pip install futures==2.2.0 enum34==1.0.4 protobuf==3.5.2.post1 six==1.10.0 t
 # Bazel installation
 
 RUN apt-get update && apt-get install -y wget && apt-get clean
-RUN wget https://github.com/bazelbuild/bazel/releases/download/0.20.0/bazel-0.20.0-installer-linux-x86_64.sh && \
-  bash ./bazel-0.20.0-installer-linux-x86_64.sh && \
-  rm bazel-0.20.0-installer-linux-x86_64.sh
+RUN wget https://github.com/bazelbuild/bazel/releases/download/0.23.2/bazel-0.23.2-installer-linux-x86_64.sh && \
+  bash ./bazel-0.23.2-installer-linux-x86_64.sh && \
+  rm bazel-0.23.2-installer-linux-x86_64.sh
 
 
 RUN mkdir -p /var/local/jenkins

tools/dockerfile/test/sanity/Dockerfile

@@ -98,9 +98,9 @@ ENV CLANG_TIDY=clang-tidy
 # Bazel installation
 
 RUN apt-get update && apt-get install -y wget && apt-get clean
-RUN wget https://github.com/bazelbuild/bazel/releases/download/0.20.0/bazel-0.20.0-installer-linux-x86_64.sh && \
-  bash ./bazel-0.20.0-installer-linux-x86_64.sh && \
-  rm bazel-0.20.0-installer-linux-x86_64.sh
+RUN wget https://github.com/bazelbuild/bazel/releases/download/0.23.2/bazel-0.23.2-installer-linux-x86_64.sh && \
+  bash ./bazel-0.23.2-installer-linux-x86_64.sh && \
+  rm bazel-0.23.2-installer-linux-x86_64.sh
 
 
 # Define the default command.

tools/internal_ci/linux/grpc_bazel_build_in_docker.sh

@@ -24,4 +24,4 @@ git clone /var/local/jenkins/grpc /var/local/git/grpc
 && git submodule update --init --reference /var/local/jenkins/grpc/${name} \
 ${name}')
 cd /var/local/git/grpc
-bazel build --spawn_strategy=standalone --genrule_strategy=standalone :all test/... examples/...
+bazel build --spawn_strategy=standalone --genrule_strategy=standalone :all test/...