address comments

Author: rahul2393

java-spanner/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GapicSpannerRpc.java

@@ -619,7 +619,6 @@ public void clearTransactionAndChannelAffinity(
       keyAwareChannel.clearTransactionAndChannelAffinity(transactionId, channelHint);
       return;
     }
-    clearTransactionAffinity(transactionId);
     GrpcGcpAffinityUtil.clearChannelHintAffinity(grpcGcpChannel, channelHint);
   }
 

java-spanner/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GrpcGcpAffinityUtil.java

@@ -33,6 +33,8 @@ static void clearChannelHintAffinity(
     if (!(channel instanceof GcpManagedChannel) || channelHint == null) {
       return;
     }
+    // TODO: Replace this synthetic call once grpc-gcp exposes a direct API for unbinding
+    // affinity keys without creating and immediately cancelling a ClientCall.
     ClientCall<ExecuteSqlRequest, ResultSet> call =
         channel.newCall(
             SpannerGrpc.getExecuteSqlMethod(),

java-spanner/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/KeyAwareChannel.java

@@ -305,9 +305,10 @@ void clearTransactionAffinity(ByteString transactionId) {
   }
 
   void clearTransactionAndChannelAffinity(ByteString transactionId, @Nullable Long channelHint) {
+    String address = transactionAffinities.remove(transactionId);
+    readOnlyTxPreferLeader.invalidate(transactionId);
     if (channelHint != null) {
       ManagedChannel channel = defaultChannel;
-      String address = transactionAffinities.get(transactionId);
       if (address != null) {
         ChannelEndpoint endpoint = endpointCache.getIfPresent(address);
         if (endpoint != null) {
@@ -316,7 +317,6 @@ void clearTransactionAndChannelAffinity(ByteString transactionId, @Nullable Long
       }
       GrpcGcpAffinityUtil.clearChannelHintAffinity(channel, channelHint);
     }
-    clearAffinity(transactionId);
   }
 
   private void maybeExcludeEndpointOnNextCall(