Fix getFrameTimestamp test flakes.

This fixes both the dEQP CTS flakes relating to
compositor timing and the lib_gui test flakes that
don't initialize properly.

Test: adb shell /data/nativetest/libgui_test/libgui_test
  --gtest_filter=*GetFrameTimestamps*
Bug: 35995043

Change-Id: If8e59f0dc9a916bab28bd1a36190cef9a56cb64f
diff --git a/include/gui/FrameTimestamps.h b/include/gui/FrameTimestamps.h
index bda3c5c..cbb4491 100644
--- a/include/gui/FrameTimestamps.h
+++ b/include/gui/FrameTimestamps.h
@@ -105,7 +105,7 @@
 struct CompositorTiming {
     nsecs_t deadline{0};
     nsecs_t interval{16666667};
-    nsecs_t presentLatency{0};
+    nsecs_t presentLatency{16666667};
 };
 
 // A short history of frames that are synchronized between the consumer and