Clean up TLS Socket Factory in key management service

JAVA-3734

Author: jyemin

driver-async/src/main/com/mongodb/async/client/internal/Crypt.java

@@ -242,6 +242,7 @@ public void close() {
             commandMarker.close();
         }
         keyRetriever.close();
+        keyManagementService.close();
     }
 
     private void executeStateMachine(final MongoCryptContext cryptContext, final String databaseName,

driver-async/src/main/com/mongodb/async/client/internal/KeyManagementService.java

@@ -40,17 +40,24 @@
 
 class KeyManagementService {
     private final int defaultPort;
+    private final TlsChannelStreamFactoryFactory tlsChannelStreamFactoryFactory;
     private final StreamFactory streamFactory;
 
     KeyManagementService(final SSLContext sslContext, final int defaultPort, final int timeoutMillis) {
         this.defaultPort = defaultPort;
-        this.streamFactory = new TlsChannelStreamFactoryFactory().create(SocketSettings.builder()
+        this.tlsChannelStreamFactoryFactory = new TlsChannelStreamFactoryFactory();
+        this.streamFactory = tlsChannelStreamFactoryFactory.create(SocketSettings.builder()
                         .connectTimeout(timeoutMillis, TimeUnit.MILLISECONDS)
                         .readTimeout(timeoutMillis, TimeUnit.MILLISECONDS)
                         .build(),
                 SslSettings.builder().enabled(true).context(sslContext).build());
     }
 
+
+    public void close() {
+        tlsChannelStreamFactoryFactory.close();
+    }
+
     void decryptKey(final MongoKeyDecryptor keyDecryptor, final SingleResultCallback<Void> callback) {
         streamOpen(keyDecryptor, callback);
     }