Prefer re2 over java.util.regex

Java's stock regex implementation doesn't guarantee linear time
complexity which makes it a security liability.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=121159875

java/google/registry/util/BUILD

@@ -28,6 +28,7 @@ java_library(
         "//third_party/java/jsr305_annotations",
         "//third_party/java/jsr330_inject",
         "//third_party/java/objectify:objectify-v4_1",
+        "//third_party/java/re2j",
         "//third_party/java/servlet/servlet_api",
         "//java/google/registry/config",
     ],