[ServiceBus] update None in network trace params to empty str

[swathipil]

updating as per Anna's comment here: #32190 (comment)

fixes: #32190

TODO:

• add tests to check _network_trace_params has been updated
• check with monitor to see if we can repro exact error
• change all name in pyamqp logging to "azure.amqp" + update docs

[azure-sdk]

API change check

API changes are not detected in this pull request.

[github-actions]

Hi @swathipil. Thank you for your interest in helping to improve the Azure SDK experience and for your contribution. We've noticed that there hasn't been recent engagement on this pull request. If this is still an active work stream, please let us know by pushing some changes or leaving a comment. Otherwise, we'll close this out in 7 days.

[github-actions]

Hi @swathipil. Thank you for your contribution. Since there hasn't been recent engagement, we're going to close this out. Feel free to respond with a comment containing /reopen if you'd like to continue working on these changes. Please be sure to use the command to reopen or remove the no-recent-activity label; otherwise, this is likely to be closed again with the next cleanup pass.