Revert "Revert "Use new onStartSplitLegacy when starting split f..."

Revert submission 17918609-revert-17779173-startSplitLegacy-OOWPZEFFGI

Reason for revert: Running through TH
Reverted Changes:
I6d81e0584:Revert "Use new onStartSplitLegacy when starting s...
I754bc308f:Revert "Remove check for preventing re-parenting n...

Change-Id: I6eea82f34b3680020b49ec7fe19eb61cc68286a5
3 files changed