hwc2: rename the enable_drop_refresh property to enable_optimize_refresh

Add change to rename the enable_drop_refresh property to
enable_optimize_refresh for better readability.

Change-Id: I379b7ef610bc0979b9a78dac607f371acfe24fbc
CRs-Fixed: 2418804
diff --git a/include/display_properties.h b/include/display_properties.h
index 470542f..a11852f 100644
--- a/include/display_properties.h
+++ b/include/display_properties.h
@@ -122,7 +122,7 @@
 #define ENABLE_QDCM_DIAG                     DISPLAY_PROP("enable_qdcm_diag")
 
 #define ZERO_SWAP_INTERVAL                   "vendor.debug.egl.swapinterval"
-#define ENABLE_DROP_REFRESH                  DISPLAY_PROP("enable_drop_refresh")
+#define ENABLE_OPTIMIZE_REFRESH              DISPLAY_PROP("enable_optimize_refresh")
 #define ENABLE_ASYNC_POWERMODE               DISPLAY_PROP("enable_async_powermode")
 #define DISABLE_UI_3D_TONEMAP                DISPLAY_PROP("disable_ui_3d_tonemap")