Add background scan capability callback broadcast radio HAL.

Bug: b/34054813
Test: it builds.
Change-Id: Idf931f2f5fd280c0af6f0154170a79f7e57747ab
diff --git a/broadcastradio/1.1/vts/functional/VtsHalBroadcastradioV1_1TargetTest.cpp b/broadcastradio/1.1/vts/functional/VtsHalBroadcastradioV1_1TargetTest.cpp
index d3c05c4..aa5ab54 100644
--- a/broadcastradio/1.1/vts/functional/VtsHalBroadcastradioV1_1TargetTest.cpp
+++ b/broadcastradio/1.1/vts/functional/VtsHalBroadcastradioV1_1TargetTest.cpp
@@ -129,6 +129,10 @@
             return Void();
         }
 
+        virtual Return<void> backgroundScanAvailable(bool isAvailable __unused) {
+            return Void();
+        }
+
         virtual Return<void> backgroundScanComplete(ProgramListResult result __unused) {
             return Void();
         }