Run checkstyle on test source files

Change-Id: If22a7e5ddacc73dbabab276e0f719d0633b6df72
diff --git a/tools/build/bazel/osgi_java_library.bzl b/tools/build/bazel/osgi_java_library.bzl
index b2505a4..bd68a30 100644
--- a/tools/build/bazel/osgi_java_library.bzl
+++ b/tools/build/bazel/osgi_java_library.bzl
@@ -514,6 +514,11 @@
             name = name + "_checkstyle_test",
             srcs = srcs,
         )
+        if test_srcs != []:
+            checkstyle_test(
+                name = name + "_checkstyle_tests_test",
+                srcs = test_srcs,
+            )
 
 """
     Creates an OSGI jar file from a set of source files.