Add java-prettify submodule

Test: bazelisk build //:gitiles && tools/run_dev.sh

Change-Id: I107354498367ec22e977e91f08e7de70d04b8573

lib/BUILD

diff --git a/lib/BUILD b/lib/BUILD
index a0dfa57..4fec826 100644
--- a/lib/BUILD
+++ b/lib/BUILD
@@ -21,7 +21,6 @@
     "gson",
     "guava",
     "guava-failureaccess",
-    "prettify",
     "ow2-asm",
     "ow2-asm-analysis",
     "ow2-asm-commons",
@@ -30,6 +29,12 @@
 ]]
 
 java_library(
+  name = "prettify",
+  visibility = ["//visibility:public"],
+  exports = ["@java-prettify"],
+)
+
+java_library(
     name = "slf4j-api",
     exports = ["@log-api//jar"],
 )