Use correct timestamp for RegionSubject

Test: N/A

Bug: 293096776
Change-Id: Id37b4be4eb012ab4369d973008dc237620a4cd35
diff --git a/tests/FlickerTests/src/com/android/server/wm/flicker/CommonAssertions.kt b/tests/FlickerTests/src/com/android/server/wm/flicker/CommonAssertions.kt
index 4d36111..abd8758 100644
--- a/tests/FlickerTests/src/com/android/server/wm/flicker/CommonAssertions.kt
+++ b/tests/FlickerTests/src/com/android/server/wm/flicker/CommonAssertions.kt
@@ -282,7 +282,7 @@
                 snapshotLayers
                     .mapNotNull { snapshotLayer -> snapshotLayer.layer.visibleRegion }
                     .toTypedArray()
-            val snapshotRegion = RegionSubject(visibleAreas, timestamp)
+            val snapshotRegion = RegionSubject(visibleAreas, it.timestamp)
             // Verify the size of snapshotRegion covers appVisibleRegion exactly in animation.
             if (snapshotRegion.region.isNotEmpty) {
                 val appVisibleRegion = it.visibleRegion(component)