Update platform source.prop for new layoutlib. do not merge.

Change-Id: Idd813cc0c69d67e1f60e23ec0b4254d26e459ba3
diff --git a/sdk/platform_source.prop_template b/sdk/platform_source.prop_template
index 8162690..1fa9060 100644
--- a/sdk/platform_source.prop_template
+++ b/sdk/platform_source.prop_template
@@ -2,9 +2,9 @@
 Pkg.UserSrc=false
 Platform.Version=${PLATFORM_VERSION}
 Platform.CodeName=Jelly Bean
-Pkg.Revision=3
+Pkg.Revision=4
 AndroidVersion.ApiLevel=${PLATFORM_SDK_VERSION}
 AndroidVersion.CodeName=${PLATFORM_VERSION_CODENAME}
-Layoutlib.Api=8
+Layoutlib.Api=9
 Layoutlib.Revision=1
-Platform.MinToolsRev=20
+Platform.MinToolsRev=21