i2s: name the tx/rx threads

Having names improves the output "machine GetClockSourceInfo".

Change-Id: If009eef1da26c196583140dab5d90273124b1c07
diff --git a/shodan_infrastructure/MatchaI2S.cs b/shodan_infrastructure/MatchaI2S.cs
index 5845f70..918ca12 100644
--- a/shodan_infrastructure/MatchaI2S.cs
+++ b/shodan_infrastructure/MatchaI2S.cs
@@ -197,7 +197,7 @@
             decoder.LoadFile(InputFile);
 
             this.Log(LogLevel.Info, "Starting recording.");
-            rxThread = machine.ObtainManagedThread(ReceiveFrame, SampleFrequencyHz);
+            rxThread = machine.ObtainManagedThread(ReceiveFrame, SampleFrequencyHz, name: "i2s rx");
             rxThread.Start();
         }
 
@@ -215,7 +215,7 @@
                     Process.GetCurrentProcess().Id, outputFileIdx++);
             encoder.SetBufferingBySamplesCount(1);
 
-            txThread = machine.ObtainManagedThread(TransmitFrame, SampleFrequencyHz);
+            txThread = machine.ObtainManagedThread(TransmitFrame, SampleFrequencyHz, name: "i2s tx");
             txThread.Start();
         }