Rename Compatibility into support and move it to rev 4. DO NOT MERGE.

Cherry-pick from master e98f22d

Change-Id: I165a7aeb429a4288d6f693a7613a4a102e21dd5b
diff --git a/sdk/support_source.properties b/sdk/support_source.properties
new file mode 100644
index 0000000..b75e326
--- /dev/null
+++ b/sdk/support_source.properties
@@ -0,0 +1,2 @@
+Pkg.UserSrc=false
+Pkg.Revision=4