Fix wrong split bounds if IME shown then rotate

We will shift split window bounds when IME shown but using bounds
in taskinfo. When rotation case, after tracing by log, it seems
sometimes we will get old bounds value before rotation then cause
split layout issue.

Fix this by using bounds computed by SplitLayout itself rather than
using bounds in taskinfo.

Fix: 238736466
Test: manual
Test: pass existing tests
Change-Id: If309858009935e8d7a1d2fa6a2b8dfc4a5004de4