Add StackDriver implementation, in monitoring/metrics package

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=130287319

third_party/java/error_prone/BUILD

@@ -0,0 +1,8 @@
+package(default_visibility = ["//visibility:public"])
+
+licenses(["notice"])  # Apache 2.0
+
+java_library(
+    name = "annotations",
+    exports = ["@error_prone_annotations//jar"],
+)