Bazel: Widen visibility of javax-annotation rule to plugins

Some of the plugins, most notably checks plugin, may want to use
java_doc Starlark rule and for that access to //lib:javax-annotation
is required.

Change-Id: Iddc907138f71fded02c76136f34e17070dc64d18

lib/BUILD

@@ -528,7 +528,7 @@ java_library(
         "//java/com/google/gerrit/acceptance:__pkg__",
         "//java/com/google/gerrit/extensions:__pkg__",
         "//java/com/google/gerrit/server:__pkg__",
-        "//plugins:__pkg__",
+        "//plugins:__subpackages__",
     ],
     exports = ["@javax-annotation//jar"],
 )