Turn on ENABLE_VIRTUAL_DISPLAY_REFRESH_RATE flag

This feature enables the creation of virtual displays with an added
parameter for requested refresh rate

Bug: 267363922
Test: refer to the sample in base/tests/VirtualDisplayEncoder
Change-Id: Ic2c8e80ee599d2280fd2f3efd9a62c08fe54c668
diff --git a/core/java/android/hardware/display/DisplayManager.java b/core/java/android/hardware/display/DisplayManager.java
index f693a2f..eeff6cc 100644
--- a/core/java/android/hardware/display/DisplayManager.java
+++ b/core/java/android/hardware/display/DisplayManager.java
@@ -66,7 +66,7 @@
 public final class DisplayManager {
     private static final String TAG = "DisplayManager";
     private static final boolean DEBUG = false;
-    private static final boolean ENABLE_VIRTUAL_DISPLAY_REFRESH_RATE = false;
+    private static final boolean ENABLE_VIRTUAL_DISPLAY_REFRESH_RATE = true;
 
     private final Context mContext;
     private final DisplayManagerGlobal mGlobal;