Merge "Add documentation for LayoutParams.preferredRefreshRate" into tm-dev am: 336fcab788 am: b217bbb695

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17955874

Change-Id: I670aa79b5d9a7727e1b8532b035f00c003032649
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

core/java/android/view/WindowManager.java

@@ -3122,10 +3122,14 @@ public interface WindowManager extends ViewManager {
 
         /**
          * The preferred refresh rate for the window.
-         *
+         * <p>
          * This must be one of the supported refresh rates obtained for the display(s) the window
          * is on. The selected refresh rate will be applied to the display's default mode.
-         *
+         * <p>
+         * This should be used in favor of {@link LayoutParams#preferredDisplayModeId} for
+         * applications that want to specify the refresh rate, but do not want to specify a
+         * preference for any other displayMode properties (e.g., resolution).
+         * <p>
          * This value is ignored if {@link #preferredDisplayModeId} is set.
          *
          * @see Display#getSupportedRefreshRates()