Add tests for VsyncSchedule

Follow-on to I54a1304a3428968134cc707b24d5b325927c31df. This is somewhat
covered by existing unit tests, but add more thorough tests just for
VsyncSchedule.

Include thread_annotations.h to fix build.

Update MockSchedulerCallback to include the new interface header.

Bug: 241286146
Test: this
Change-Id: I79e14d67fea896752f0afaba00adc6d47efc3c71
Merged-In: I79e14d67fea896752f0afaba00adc6d47efc3c71
diff --git a/services/surfaceflinger/Scheduler/VsyncSchedule.h b/services/surfaceflinger/Scheduler/VsyncSchedule.h
index d88f1d1..a32acc7 100644
--- a/services/surfaceflinger/Scheduler/VsyncSchedule.h
+++ b/services/surfaceflinger/Scheduler/VsyncSchedule.h
@@ -20,6 +20,7 @@
 #include <string>
 
 #include <ThreadContext.h>
+#include <android-base/thread_annotations.h>
 #include <ftl/enum.h>
 #include <ftl/optional.h>
 #include <scheduler/Features.h>
@@ -27,6 +28,7 @@
 
 namespace android {
 class EventThreadTest;
+class VsyncScheduleTest;
 }
 
 namespace android::fuzz {
@@ -96,6 +98,7 @@
 private:
     friend class TestableScheduler;
     friend class android::EventThreadTest;
+    friend class android::VsyncScheduleTest;
     friend class android::fuzz::SchedulerFuzzer;
 
     using TrackerPtr = std::unique_ptr<VsyncTracker>;