Assign previous release fence to previous frame ID

...as otherwise the release timestamps for EGL/Vk timing apis are
shifted by one frame.

Bug: 295456126
Bug: 301055892
Bug: 303385401
Bug: 310927247
Test: Log and inspect timestamps
Change-Id: If1d8a525053591f15b95aeec8dc0bad8a13e6833
diff --git a/libs/gui/libgui_flags.aconfig b/libs/gui/libgui_flags.aconfig
index a16be78..b081030 100644
--- a/libs/gui/libgui_flags.aconfig
+++ b/libs/gui/libgui_flags.aconfig
@@ -8,3 +8,10 @@
   is_fixed_read_only: true
 }
 
+flag {
+  name: "frametimestamps_previousrelease"
+  namespace: "core_graphics"
+  description: "Controls a fence fixup for timestamp apis"
+  bug: "310927247"
+  is_fixed_read_only: true
+}