Generate onos_app rule

There are three genrules:
 1. Build features.xml
 2. Build app.xml
 3. Generate app.oar

Change-Id: I6adfd47fadf40ad2440998071a01894458629ac6
diff --git a/buck-tools/default.defs b/buck-tools/default.defs
index 5ed0fea..24caa38 100644
--- a/buck-tools/default.defs
+++ b/buck-tools/default.defs
@@ -1,9 +1,10 @@
 include_defs('//bucklets/maven_jar.bucklet')
 include_defs('//bucklets/onos.bucklet')
+include_defs('//bucklets/onos_app.bucklet')
 
 BASE_DEPS = [
     '//lib:junit',
     '//lib:hamcrest-all',
     '//lib:slf4j-api',
     '//lib:guava-testlib',
-]
+]
\ No newline at end of file