Build song subtitle string via android getString() parameters

app/src/main/res/values/strings.xml

@@ -196,6 +196,7 @@
     <string name="song_list_page_title">Songs</string>
     <string name="song_list_page_top">%1$s\'s top tracks</string>
     <string name="song_list_page_year">Year %1$d</string>
+    <string name="song_subtitle_formatter">%1$s  •  %2$s</string>
     <string name="starred_sync_dialog_negative_button">Cancel</string>
     <string name="starred_sync_dialog_positive_button">Continue</string>
     <string name="starred_sync_dialog_summary">Tracks will be downloaded in their original format. Standard data rates may apply.</string>