AntennaPod gets a Next chapter button in the car

AntennaPod takes the command whenever it plays, but only offers the
button when it's turned on in its own notification settings.

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

@@ -877,4 +877,5 @@
     <string name="places_clear">Clear</string>
     <string name="settings_language">Language</string>
     <string name="settings_language_phone">Same as the phone</string>
+    <string name="player_next_chapter">Next chapter</string>
 </resources>