improve status reporting in yubikey dialogue

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

@@ -1269,5 +1269,9 @@
     <string name="unlocked">Unlocked</string>
     <string name="nfc_settings">Settings</string>
     <string name="snack_yubikey_view">View</string>
+    <string name="button_bind_key">Bind Key</string>
+    <string name="yubikey_serno">"Serial No: %s"</string>
+    <string name="yubikey_key_holder">"Key holder: "</string>
+    <string name="yubikey_key_holder_unset">"Key holder: &lt;unset&gt;"</string>
 
 </resources>