Merge "Revert "Use new onStartSplitLegacy when starting split from overview"" into tm-dev am: 8340cb6d7d am: 78194ca6ad

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/17918609

Change-Id: I2d68fd2a3348c2ca7bede5a189e93c14b34b8826
Ignore-AOSP-First: this is an automerge
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>