Create the flingFeed() and getScrollContainer() for INotificationHelper

Bug: 164004711
Test: Run pts/cuj/scroll/notification

Change-Id: Ifc99f2d92a54f63504668b935a6b99556723b400
diff --git a/libraries/app-helpers/interfaces/handheld/src/android/platform/helpers/INotificationHelper.java b/libraries/app-helpers/interfaces/handheld/src/android/platform/helpers/INotificationHelper.java
index 4babad1..704874a 100644
--- a/libraries/app-helpers/interfaces/handheld/src/android/platform/helpers/INotificationHelper.java
+++ b/libraries/app-helpers/interfaces/handheld/src/android/platform/helpers/INotificationHelper.java
@@ -18,6 +18,7 @@
 
 import android.app.Notification;
 import android.support.test.uiautomator.BySelector;
+import android.support.test.uiautomator.Direction;
 import android.support.test.uiautomator.UiObject2;
 
 import androidx.annotation.Nullable;
@@ -210,4 +211,38 @@
     default void shareScreenshotFromNotification(BySelector pageSelector) {
         throw new UnsupportedOperationException("Not yet implemented.");
     }
+
+    /**
+     * Setup expectation: On the expanding notification screen.
+     *
+     * <p>Get the UiObject2 of expanding notification screen.
+     */
+    default UiObject2 getNotificationShadeScrollContainer() {
+        throw new UnsupportedOperationException("Not yet implemented.");
+    }
+
+    /**
+     * Scroll feeds on Notifications screen
+     *
+     * <p>Setup expectations: Notification is open with lots of notifications.
+     *
+     * @param container The container with scrollable elements.
+     * @param dir The direction of the fling, must be UP or DOWN.
+     */
+    default void flingFeed(UiObject2 container, Direction dir) {
+        throw new UnsupportedOperationException("Not yet implemented.");
+    }
+
+    /**
+     * Scroll feeds on Notifications screen
+     *
+     * <p>Setup expectations: Notification is open with lots of notifications.
+     *
+     * @param container The container with scrollable elements.
+     * @param dir The direction of the scroll, must be UP or DOWN.
+     * @param speed The speed of fling.
+     */
+    default void flingFeed(UiObject2 container, Direction dir, int speed) {
+        throw new UnsupportedOperationException("Not yet implemented.");
+    }
 }