Add background scan capability callback broadcast radio HAL.

Bug: b/34054813
Test: it builds.
Change-Id: Idf931f2f5fd280c0af6f0154170a79f7e57747ab
diff --git a/broadcastradio/1.1/ITuner.hal b/broadcastradio/1.1/ITuner.hal
index 82d45c6..dc74eb9 100644
--- a/broadcastradio/1.1/ITuner.hal
+++ b/broadcastradio/1.1/ITuner.hal
@@ -47,8 +47,8 @@
      *
      * @return result OK if the scan was properly scheduled (this does not mean
      *                it successfully finished).
-     *                TEMPORARILY_UNAVAILABLE if the background scan is
-     *                temporarily unavailable, ie. due to ongoing foreground
+     *                UNAVAILABLE if the background scan is unavailable,
+     *                ie. temporarily due to ongoing foreground
      *                playback in single-tuner device.
      *                NOT_INITIALIZED other error, ie. HW failure.
      */