Bazel: Simplify diffy_logo rules

There is a regression in Bazel 0.3.2 release: [1] that prevents creating
a symbolic link to previously built artifact. In this case we don't
really need to do that, as we can depend on previously built library and
do not need to create a zip from java_library and import it again as
java_library.

[1] https://github.com/bazelbuild/bazel/issues/1966

Change-Id: I16a62e2fbb3e2d1de377eeef70061298bb2bb745

gerrit-gwtui-common/BUILD

@@ -13,7 +13,6 @@ EXPORTED_DEPS = [
 ]
 DEPS = ['//lib/gwt:user']
 SRC = 'src/main/java/com/google/gerrit/'
-DIFFY = glob(['src/main/resources/com/google/gerrit/client/diffy*.png'])
 
 gwt_module(
   name = 'client',
@@ -38,26 +37,14 @@ java_library2(
   visibility = ['//visibility:public'],
 )
 
-java_import(
+java_library(
   name = 'diffy_logo',
-  jars = [':diffy_image_files_ln'],
-  visibility = ['//visibility:public'],
+  resources = glob(['src/main/resources/com/google/gerrit/client/diffy*.png']),
   data = [
     '//lib:LICENSE-diffy',
     '//lib:LICENSE-CC-BY3.0-unported',
   ],
-)
-
-genrule2(
-  name = 'diffy_image_files_ln',
-  srcs = [':diffy_image_files'],
-  cmd = 'ln -s $$ROOT/$(location :diffy_image_files) $@',
-  out = 'diffy_images.jar',
-)
-
-java_library(
-  name = 'diffy_image_files',
-  resources = DIFFY,
+  visibility = ['//visibility:public'],
 )
 
 junit_tests(