Add a method to get the device suggestion pill from MediaController

Bug: 418227608
Flag: EXEMPT Scenario Test
Test: atest
android.platform.test.scenario.sysui.media.MediaWithDeviceSuggestionRenderTest
(with corresponding changes in MediaWithDeviceSuggestionRenderTest)

Change-Id: I3daf7b6291af01b65fbc6eeaa507ee7b51df3fdb
diff --git a/libraries/systemui-helper/src/android/platform/helpers/media/MediaController.java b/libraries/systemui-helper/src/android/platform/helpers/media/MediaController.java
index 69a6b1d..212fbab 100644
--- a/libraries/systemui-helper/src/android/platform/helpers/media/MediaController.java
+++ b/libraries/systemui-helper/src/android/platform/helpers/media/MediaController.java
@@ -205,6 +205,11 @@
         return mDevice.swipe(startX, bound.centerY(), endX, bound.centerY(), 10);
     }
 
+    public UiObject2 deviceSuggestionPill() {
+        return mUiObject.wait(
+                Until.findObject(By.res(PKG, "device_suggestion_button")), WAIT_TIME_MILLIS);
+    }
+
     public Rect getVisibleBound() {
         return mUiObject.getVisibleBounds();
     }