Install clang-9 and clang-10 in ubuntu1804 container (for Envoy)
Install clang-9 and clang-10 in ubuntu1804 container (for Envoy)

bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration