Add getSourceSets on extension object.

Change-Id: Ifed369c3e397c031326c10778d17241eb3f6cccf
diff --git a/changelog.txt b/changelog.txt
index 91db840..55048fc 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -4,6 +4,7 @@
    - Fix support for subfolders in assets/
    - Fix cases where Android Libraries have local Jars dependencies
    - Fix renaming of package through DSL to ensure resources are compiled in the new namespace
+   - Fix DSL to add getSourceSets on the "android" extension.
 
 0.3