Fix build

Change-Id: I9498ecda9b05c7166faf9f648f0b61682a88c4da
diff --git a/media/java/android/media/tv/TvContract.java b/media/java/android/media/tv/TvContract.java
index eed24d2a..82c5a8e 100644
--- a/media/java/android/media/tv/TvContract.java
+++ b/media/java/android/media/tv/TvContract.java
@@ -1312,6 +1312,7 @@
 
             private static final char DOUBLE_QUOTE = '"';
             private static final char COMMA = ',';
+            private static final String DELIMITER = ",";
 
             private Genres() {}
 
@@ -1327,7 +1328,7 @@
                 String separator = "";
                 for (String genre : genres) {
                     sb.append(separator).append(encodeToCsv(genre));
-                    separator = COMMA;
+                    separator = DELIMITER;
                 }
                 return sb.toString();
             }