Fix old edgeAgent remaining

[suzusuzu]

Fix #6241

I have added a fix to always remove the old edgeAgent on startup of aziot-edged.

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[nimanch]

/azp run

[nimanch]

/azp run

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[gordonwang0]

This will cause edgeAgent to be recreated every time Edge Daemon restarts, even if there are no changes to edgeAgent. This is unnecessary and not what we want to do.

A better fix would be to change iotedge config apply to remove edgeAgent if edgeAgent's config changes.

[suzusuzu]

@gordonwang0
Thanks for the review.
I understood, I would like to modify the implementation to remove edgeAgent only if edgeAgent's config changes.

[suzusuzu]

@gordonwang0
I have fixed it. Could you review it again?

[gordonwang0]

You won't be able to diff old/new configs from the watchdog; you'll have to change the iotedge tool to diff them before it writes out the new config. That may be a larger change for us to to.