- added handling of call security including update of status icon

- added security and zid variables to Call object
- added media encryption variable to Account object

app/src/main/kotlin/com/tutpro/baresip/Call.kt

@@ -5,4 +5,6 @@ import android.text.TextWatcher
 class Call(val ua: String, val call: String, val peerURI: String, var status: String,
            val dtmfWatcher: TextWatcher?) {
     var hold: Boolean = false
+    var security: Int = 0
+    var zid: String = ""
 }