Bump minimum bazel version check to 0.19, to avoid the following error, which isn't helpful:

ERROR: cc_toolchain_suite '@local_config_cuda//crosstool:toolchain' does not contain a toolchain for CPU 'k8', you may want to add an entry for 'local|compiler' into toolchains and toolchain_identifier 'local_linux' into the corresponding cc_toolchain rule (see --incompatible_disable_cc_toolchain_label_from_crosstool_proto).
PiperOrigin-RevId: 225430355