Have moveActivityToStack API set focus activity or stack.

Without setting the focus activity or stack, activity manager
is left in a bad set.

Also, fixed issue with resizeTask API not moving a previously
focused task new stack to the front.

Bug: 23041817
Change-Id: I6e1acc31e94e2c3d95fbbd3d5dc6bb66e5396c4a
2 files changed