Bazel: Adapt RBE to produce Java 11 language level

In I79434c657bd language level was changed to Java 11 per default, but
in remote build configuration this switch was missed.

Switch RBE auto configuration to use JDK 11. The output generated is
major bytecode version 55 that won't run on Java 8.

Test Plan:

  $ bazel test \
      --config=remote \
      --remote_instance_name=<project-name> \
      javatests/...

Change-Id: Ifdabbea9517306ee48c3a85b1b04f6f01878597c
diff --git a/WORKSPACE b/WORKSPACE
index 0a7d635..fcd4d5a 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -45,9 +45,11 @@
 load("@bazel_toolchains//rules:rbe_repo.bzl", "rbe_autoconfig")
 
 # Creates a default toolchain config for RBE.
-# Use this as is if you are using the rbe_ubuntu16_04 container,
-# otherwise refer to RBE docs.
-rbe_autoconfig(name = "rbe_default")
+rbe_autoconfig(
+    name = "rbe_jdk11",
+    java_home = "/usr/lib/jvm/11.29.3-ca-jdk11.0.2/reduced",
+    use_checked_in_confs = "Force",
+)
 
 http_archive(
     name = "com_google_protobuf",