Add revision for platform/build

BUG:25567907
Change-Id: I21e8eb5acbb09d4c3db2d9b3a96ee591275741ac
diff --git a/default.xml b/default.xml
index cc07989..4dab5c6 100644
--- a/default.xml
+++ b/default.xml
@@ -8,7 +8,7 @@
            remote="aosp"
            sync-j="4" />
 
-  <project path="build" name="platform/build" groups="pdk" >
+  <project path="build" name="platform/build" revision="marshmallow-cts-dev" groups="pdk" >
     <copyfile src="core/root.mk" dest="Makefile" />
   </project>
   <project path="abi/cpp" name="platform/abi/cpp" groups="pdk" />