Migrate task intent/info to new task only if source task is empty

Migrate the task intent and info to the new task only if the
source task is empty or is about to remove. Or the source task will
be trimmed from Recents due to newly created task added.

Bug: 205215708
Test: start tips from Settings

Change-Id: I283b777b20f702b49fcf06fd7435bab87816d7d5