Support for setting stack windowing mode

We currently create a in stack in the windowing mode we want anytime we
want to change the windowing mode of a task which isn't optimal.
We now change the current stack windowing mode for some cases vs.
creating a new stack.

Test: go/wm-smoke
Bug: 64146578
Fixes: 68948655
Fixes: 65739235
Fixes: 29068935
Change-Id: I9fceb7d608e86610c1fb5ba59b15087a96e7401e