Adding means to build java source jars.

Change-Id: Idceb84b503dad9fe12c73e153328226b9cfeb2cf
diff --git a/tools/build/bazel/osgi_java_library.bzl b/tools/build/bazel/osgi_java_library.bzl
index c135991..5ba5e91 100644
--- a/tools/build/bazel/osgi_java_library.bzl
+++ b/tools/build/bazel/osgi_java_library.bzl
@@ -18,6 +18,7 @@
 load("//tools/build/bazel:variables.bzl", "ONOS_VERSION")
 load("//tools/build/bazel:generate_test_rules.bzl", "generate_test_rules")
 load("//tools/build/bazel:checkstyle.bzl", "checkstyle_test")
+load("//tools/build/bazel:java_sources.bzl", "java_sources")
 load("//tools/build/bazel:javadoc.bzl", "javadoc")
 
 def _all_java_sources():
@@ -463,6 +464,10 @@
         include_resources = _include_resources_to_string(include_resources),
     )
 
+    # rule for building source jars
+    if not suppress_javadocs:
+      java_sources(name = name + "-sources", srcs = srcs, visibility = visibility)
+
     # rule for building javadocs
     if not suppress_javadocs:
       javadoc(name = name + "-javadocs", deps = deps, srcs = srcs, visibility = visibility)