[DemoIntegrateRN]TestConnectNative2.js

// Send a message to native code
TestConnectNative.sendMessage(this.state.messageToNative);
// Send a callback to native code and receive a message from it
TestConnectNative.sendCallback((nativeMessage) => {
  console.log(`This log is from js code callback with native message: "${nativeMessage}"`);
});
// Exit RN to go back to native
TestConnectNative.exitRN(rootTag);