SF: Add missing ATRACE_TAG to VsyncSchedule.cpp

Enable ATRACE logging from VsyncSchedule.cpp which is needed for debugging.

Test: collect systraces with debug.sf.show_predicted_vsync set to true
      and observe VSYNC-predicted track
Change-Id: Id23fa2f0004319f4ee592e19dc34a6b74cdb644f
Bug: 235566681
diff --git a/services/surfaceflinger/Scheduler/VsyncSchedule.cpp b/services/surfaceflinger/Scheduler/VsyncSchedule.cpp
index e611658..3a918a1 100644
--- a/services/surfaceflinger/Scheduler/VsyncSchedule.cpp
+++ b/services/surfaceflinger/Scheduler/VsyncSchedule.cpp
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+
 #include <scheduler/Fps.h>
 #include <scheduler/Timer.h>