Manifest for Gradle Plugin Release 3.1.2

Change-Id: Iae5aadbcbee0df145e77c889e6956f19053de801
diff --git a/default.xml b/default.xml
index a22525f..ab44a98 100644
--- a/default.xml
+++ b/default.xml
@@ -4,7 +4,7 @@
   <remote  name="aosp"
            fetch=".."
            review="https://android-review.googlesource.com/" />
-  <default revision="studio-master-dev"
+  <default revision="refs/tags/gradle_3.1.2"
            remote="aosp"
            sync-j="4" />