Remove release fence flags

ce_fence_promise and screenshot_fence_preservation flags
have been out for several releases. They can be deleted,
along with any obsolete code related to the flag removal.

Bug: 351894825
Test: atest SurfaceFlinger_test
Flag: EXEMPT flag removal
Change-Id: Iba6166358c96ff6cfe5c64b68640fcd992c4089f
diff --git a/services/surfaceflinger/LayerFE.cpp b/services/surfaceflinger/LayerFE.cpp
index b05f0ee..f64ba9e 100644
--- a/services/surfaceflinger/LayerFE.cpp
+++ b/services/surfaceflinger/LayerFE.cpp
@@ -26,7 +26,6 @@
 
 #include "LayerFE.h"
 #include "SurfaceFlinger.h"
-#include "common/FlagManager.h"
 #include "ui/FenceResult.h"
 #include "ui/LayerStack.h"
 
@@ -84,8 +83,7 @@
     // Ensures that no promise is left unfulfilled before the LayerFE is destroyed.
     // An unfulfilled promise could occur when a screenshot is attempted, but the
     // render area is invalid and there is no memory for the capture result.
-    if (FlagManager::getInstance().ce_fence_promise() &&
-        mReleaseFencePromiseStatus == ReleaseFencePromiseStatus::INITIALIZED) {
+    if (mReleaseFencePromiseStatus == ReleaseFencePromiseStatus::INITIALIZED) {
         setReleaseFence(Fence::NO_FENCE);
     }
 }