Bazel powered Java testing (#8506)

* Protobuf Java/Core Tests running w/ Bazel.

Also integrates rules_jvm_external and migrates existing maven deps
in place.

* Add test_suite target that maps to rule name.

* Lite tests passing in Bazel

* util tests passing with Bazel.

* Add conformance and build testing to //java:core

* Cleanup bzl style and lock down access to failure lists.

* Adding Java Lite conformance tests.

* rm newline

* parameterize conformance_test

This makes usage of failure lists more explicit.

* restrict visibility more for newly added libs and fix formatting.

* fix formatting and visibility.

* move testing.bzl to an internal package.

* fix file formatting.

* moving conformance_test to internal.bzl
diff --git a/java/BUILD b/java/BUILD
new file mode 100644
index 0000000..8778bf9
--- /dev/null
+++ b/java/BUILD
@@ -0,0 +1,8 @@
+test_suite(
+  name = "tests",
+  tests = [
+    "//java/core:tests",
+    "//java/lite:tests",
+    "//java/util:tests",
+  ],
+)