Cherry Pick: #1405 polyphase channelizer thread leak.

build.gradle

@@ -28,7 +28,7 @@ repositories {
     maven { url "https://jitpack.io" }
 }
 
-version = '0.5.1'
+version = '0.5.2'
 sourceCompatibility = '17'
 
 sourceSets {

src/main/java/io/github/dsheirer/dsp/filter/channelizer/PolyphaseChannelSource.java

@@ -28,11 +28,12 @@ import io.github.dsheirer.source.SourceEvent;
 import io.github.dsheirer.source.tuner.channel.StreamProcessorWithHeartbeat;
 import io.github.dsheirer.source.tuner.channel.TunerChannel;
 import io.github.dsheirer.source.tuner.channel.TunerChannelSource;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.locks.ReentrantLock;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /**
  * Polyphase Channelizer's Tuner Channel Source implementation.  Wraps a ChannelOutputProcessor instance and
@@ -201,6 +202,7 @@ public class PolyphaseChannelSource extends TunerChannelSource implements Listen
                 if(mPolyphaseChannelOutputProcessor != null)
                 {
                     mPolyphaseChannelOutputProcessor.setListener(null);
+                    mPolyphaseChannelOutputProcessor.stop();
                 }
 
                 mPolyphaseChannelOutputProcessor = null;