Add DBus binding generator

Bug: 22608897

default.xml

@@ -117,6 +117,7 @@
   <project path="external/conscrypt" name="platform/external/conscrypt" groups="pdk-cw-fs" />
   <project path="external/curl" name="platform/external/curl" />
   <project path="external/dbus" name="platform/external/dbus" />
+  <project path="external/dbus-binding-generator" name="platform/external/dbus-binding-generator" />
   <project path="external/deqp" name="platform/external/deqp" />
   <project path="external/dexmaker" name="platform/external/dexmaker" groups="pdk-cw-fs" />
   <project path="external/dhcpcd" name="platform/external/dhcpcd" groups="pdk-cw-fs" />