Update SDK files to API 12/Android 3.1

Change-Id: I630413dab4f6859623a9c1aa44b54abe6ef392b8
diff --git a/sdk/plat_tools_source.properties b/sdk/plat_tools_source.properties
index f23e52a..b75e326 100644
--- a/sdk/plat_tools_source.properties
+++ b/sdk/plat_tools_source.properties
@@ -1,2 +1,2 @@
 Pkg.UserSrc=false
-Pkg.Revision=3
+Pkg.Revision=4