[SF] Change VSyncDispatchTimerQueue::Schedule to return ScheduleResult

Removes the optional return as Schedule always returns value.

BUG: 284845445
Test: atest VSyncDispatchTimerQueueTest
Change-Id: I5b0dd11144ff5df227a9fa23a3a3ded3b50f3ea2
diff --git a/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.h b/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.h
index afb67ae..252c09c 100644
--- a/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.h
+++ b/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.h
@@ -48,8 +48,7 @@
     std::optional<nsecs_t> lastExecutedVsyncTarget() const;
 
     // This moves the state from disarmed->armed and will calculate the wakeupTime.
-    std::optional<ScheduleResult> schedule(VSyncDispatch::ScheduleTiming, VSyncTracker&,
-                                           nsecs_t now);
+    ScheduleResult schedule(VSyncDispatch::ScheduleTiming, VSyncTracker&, nsecs_t now);
     // This will update armed entries with the latest vsync information. Entry remains armed.
     void update(VSyncTracker&, nsecs_t now);