Added button to turn microphone on/off during call

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

@@ -32,6 +32,14 @@ class Call(val callp: String, val ua: UserAgent, val peerUri: String, val dir: S
         return call_hold(callp)
     }
 
+    fun isMuted(): Boolean {
+        return call_ismuted(callp)
+    }
+
+    fun mute(mute: Boolean) {
+        call_mute(callp, mute)
+    }
+
     fun unhold(): Int {
         return call_unhold(callp)
     }
@@ -64,6 +72,8 @@ class Call(val callp: String, val ua: UserAgent, val peerUri: String, val dir: S
     private external fun call_connect(callp: String, peer_uri: String): Int
     private external fun call_hold(callp: String): Int
     private external fun call_unhold(callp: String): Int
+    private external fun call_ismuted(callp: String): Boolean
+    private external fun call_mute(callp: String, mute: Boolean)
     private external fun call_transfer(callp: String, peer_uri: String): Int
     private external fun call_send_digit(callp: String, digit: Char): Int
     private external fun call_notify_sipfrag(callp: String, code: Int, reason: String)