Allow layoutlib to access core-libart

layoutlib is one of the existing direct users of core-libart,
but was not listed in visibility because it was in Make.  Add
it to visiblility to allow converting it to Soong.

Bug: 122333007
Test: m temp_layoutlib
Change-Id: I73d0c091e26e0d622cbe1459922f35d875bc14b7
diff --git a/JavaLibrary.bp b/JavaLibrary.bp
index fb47d52..18a860f 100644
--- a/JavaLibrary.bp
+++ b/JavaLibrary.bp
@@ -256,6 +256,7 @@
         "//external/robolectric-shadows",
         "//external/wycheproof",
         "//libcore/benchmarks",
+        "//frameworks/layoutlib",
     ],
     defaults: ["libcore_java_defaults"],
     installable: true,