Support non-disposed render in tests

Change the main API to return render session so it can be
disposed by the caller later

Bug: 150331000
Test: Able to test it locally
Change-Id: I422e2d6929724a022493a7b89b7deaf27b22dff1
(cherry picked from commit 634631005c6f284d8a87f90d5f3b5e4d04483d76)
1 file changed