Don't set incorrect stack bounds when rotating screen in docked mode

Both window manager and activity manager could decide what the bounds
of other stacks should be when the docked stack exist which can get
out of sync. Now window manager does the bounds calculation and
activity manager asks window manager what the bounds should be when
it needs to resize the stack.

Bug: 24738105
Change-Id: I97356f008b676d2f58a8b54fdb08735ab51394af