[grid] Passing language env var to child containers

Closes #11629

Author: diemol

java/src/org/openqa/selenium/grid/node/docker/DockerSessionFactory.java

@@ -314,7 +314,8 @@ private Map<String, String> getBrowserContainerEnvVars(Capabilities sessionReque
     // Passing env vars set to the child container
     Map<String, String> seEnvVars = System.getenv();
     seEnvVars.entrySet().stream()
-      .filter(entry -> entry.getKey().startsWith("SE_"))
+      .filter(entry -> entry.getKey().startsWith("SE_") ||
+                       entry.getKey().equalsIgnoreCase("LANGUAGE"))
       .forEach(entry -> envVars.put(entry.getKey(), entry.getValue()));
     return envVars;
   }