move adv tls changes to another PR.

Author: rmehta19

gax-java/gax-grpc/src/main/java/com/google/api/gax/grpc/InstantiatingGrpcChannelProvider.java

@@ -67,8 +67,6 @@
 import io.grpc.TlsChannelCredentials;
 import io.grpc.alts.GoogleDefaultChannelCredentials;
 import io.grpc.auth.MoreCallCredentials;
-import io.grpc.util.AdvancedTlsX509KeyManager;
-import io.grpc.util.AdvancedTlsX509TrustManager;
 import java.io.File;
 import java.io.IOException;
 import java.lang.reflect.Method;
@@ -80,7 +78,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.Executor;
-import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 import java.util.logging.Level;
@@ -563,32 +560,13 @@ ChannelCredentials buildS2AChannelCredentials(
    */
   @VisibleForTesting
   ChannelCredentials createMtlsToS2AChannelCredentials(
-      File trustBundle, File privateKey, File certChain)
-      throws IOException, GeneralSecurityException {
+      File trustBundle, File privateKey, File certChain) throws IOException {
     if (trustBundle == null || privateKey == null || certChain == null) {
       return null;
     }
-    AdvancedTlsX509KeyManager keyManager = new AdvancedTlsX509KeyManager();
-    ScheduledExecutorService keyManagerExecutor = Executors.newSingleThreadScheduledExecutor(
-        r -> {
-          Thread t = new Thread(r, "s2a-key-manager-updater");
-          t.setDaemon(true);
-          return t;
-        });
-
-    keyManager.updateIdentityCredentials(certChain, privateKey, 1, TimeUnit.HOURS, keyManagerExecutor);
-    AdvancedTlsX509TrustManager trustManager = AdvancedTlsX509TrustManager.newBuilder().build();
-    ScheduledExecutorService trustManagerExecutor = Executors.newSingleThreadScheduledExecutor(
-        r -> {
-          Thread t = new Thread(r, "s2a-trust-manager-updater");
-          t.setDaemon(true);
-          return t;
-        });
-
-    trustManager.updateTrustCredentials(trustBundle, 1, TimeUnit.HOURS, trustManagerExecutor);
     return TlsChannelCredentials.newBuilder()
-        .keyManager(keyManager)
-        .trustManager(trustManager)
+        .keyManager(privateKey, certChain)
+        .trustManager(trustBundle)
         .build();
   }