Content description for the addresses expander image button

Signed-off-by: Peter Vágner <pvdeejay@gmail.com>

app/src/main/java/eu/faircode/email/AdapterMessage.java

@@ -1144,6 +1144,7 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
 
             // Addresses
             ibExpanderAddress.setImageLevel(show_addresses ? 0 /* less */ : 1 /* more */);
+            ibExpanderAddress.setContentDescription(context.getString(show_addresses ? R.string.title_accessibility_hide_addresses : R.string.title_accessibility_show_addresses));
 
             String from = MessageHelper.formatAddresses(message.senders);
             String to = MessageHelper.formatAddresses(message.to);