Merge "Check if last resumed activity is null before resuming." into pi-dev

                    if (DEBUG_STATES) Slog.v(TAG_STATES, "Resume failed; resetting state to "

                            + lastState + ": " + next);

                    next.setState(lastState, "resumeTopActivityInnerLocked");

                    if (lastStack != null) {

                    // lastResumedActivity being non-null implies there is a lastStack present.

                    if (lastResumedActivity != null) {

                        lastResumedActivity.setState(RESUMED, "resumeTopActivityInnerLocked");

                    }

                    Slog.i(TAG, "Restarting because process died: " + next);

                    if (!next.hasBeenLaunched) {

                        next.hasBeenLaunched = true;