Build: enable python3 by default

docker/build/installers/install_bazel.sh

@@ -74,10 +74,6 @@ elif [ "$TARGET_ARCH" == "aarch64" ]; then
       apt-get -y install \
       build-essential openjdk-11-jdk python3 zip unzip
 
-    if [[ ! -e /usr/bin/python ]]; then
-        ln -s /usr/bin/python3 /usr/local/bin/python
-    fi
-
     PKG_NAME="bazel-${VERSION}-dist.zip"
     CHECKSUM="44ec129436f6de45f2230e14100104919443a1364c2491f5601666b358738bfa"
     DOWNLOAD_LINK="https://github.com/bazelbuild/bazel/releases/download/${VERSION}/${PKG_NAME}"

docker/build/installers/install_minimal_environment.sh

@@ -91,6 +91,7 @@ sed -i /etc/sudoers -re 's/^%sudo.*/%sudo ALL=(ALL:ALL) NOPASSWD: ALL/g'
 ##----------------##
 ## Python Setings |
 ##----------------##
+update-alternatives --install /usr/bin/python python /usr/bin/python3 36
 
 if [[ "${MY_GEO}" == "cn" ]]; then
     # configure tsinghua's pypi mirror for x86_64 and aarch64