Add mShouldPerformActiveScan to RouteDiscoveryPreference#dump

Bug: 205124386
Change-Id: Ia9457568662e2014d0d831667f9ebc0f59069d61
Test: adb shell dumpsys media_router
diff --git a/media/java/android/media/RouteDiscoveryPreference.java b/media/java/android/media/RouteDiscoveryPreference.java
index 71d8261..161fd2f 100644
--- a/media/java/android/media/RouteDiscoveryPreference.java
+++ b/media/java/android/media/RouteDiscoveryPreference.java
@@ -194,6 +194,7 @@
 
         String indent = prefix + "  ";
 
+        pw.println(indent + "mShouldPerformActiveScan=" + mShouldPerformActiveScan);
         pw.println(indent + "mPreferredFeatures=" + mPreferredFeatures);
         pw.println(indent + "mPackageOrder=" + mPackageOrder);
         pw.println(indent + "mAllowedPackages=" + mAllowedPackages);