Merge "Make lock task check if focused better" into lmp-mr1-dev

                task = mStackSupervisor.anyTaskForIdLocked(task.taskId);

                if (task != null) {

                    if (!isSystemInitiated

                            && ((mFocusedActivity == null) || (task != mFocusedActivity.task))) {

                            && ((mStackSupervisor.getFocusedStack() == null)

                                    || (task != mStackSupervisor.getFocusedStack().topTask()))) {

                        throw new IllegalArgumentException("Invalid task, not in foreground");

                    }

                    mStackSupervisor.setLockTaskModeLocked(task, !isSystemInitiated);