Fix bubble task inheriting freeform windowing mode.

Prevent bubble tasks from inheriting the windowing mode from their
source task if the source is in freeform mode. This fixes an issue where
launching a recycled bubble task from a trampoline activity in desktop
mode would incorrectly change its windowing mode to freeform.

The expected behavior is for the bubbled task to relaunch and expand
while remaining in multi-window mode. This allows the shell
DefaultMixedHandler (LaunchNewTaskBubbleForExistingTransition) to
process the transition correctly, avoiding an unnecessary windowing mode
change in the WM core.

Bug: 432606505
Flag: EXEMPT BUGFIX
Test: atest WmTests:TaskLaunchParamsModifierTests
Change-Id: I4f55dd764e4f52fdad25826b5b92d23f9ea325cc