Fix bug: state not updated when GRPC auto reconnect to the same server (#3181)

package org.apache.skywalking.apm.agent.core.remote;

import io.grpc.Channel;

import io.grpc.ConnectivityState;

import io.grpc.ManagedChannel;

import io.grpc.ManagedChannelBuilder;

import io.grpc.netty.NettyChannelBuilder;

        return originChannel.isShutdown();

    }

    public boolean isConnected() {

        return originChannel.getState(false) == ConnectivityState.READY;

    }

    public static class Builder {

        private final String host;

        private final int port;

                            .build();

                        notify(GRPCChannelStatus.CONNECTED);

                        reconnect = false;

                    } else if (managedChannel.isConnected()) {

                        // Reconnect to the same server is automatically done by GRPC,

                        // therefore we are responsible to check the connectivity and

                        // set the state and notify listeners

                        notify(GRPCChannelStatus.CONNECTED);

                        reconnect = false;

                    }

                    reconnect = false;

                    return;

                } catch (Throwable t) {

                    logger.error(t, "Create channel to {} fail.", server);