Fix waagent overriding SSH public key from Ignition configuration

[peytonr18]

Description

This PR resolves an issue where the WALinuxAgent overrides the SSH public key provided by Ignition configuration during provisioning. The issue is related to this ongoing ICM, and applies the fix given for resolving the issue.

Issue #

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PR information

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• New Unit tests were added for the changes made

Quality of Code and Contribution Guidelines

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[maddieford]

@jasonzio Could we please get your review on this one too?

[jasonzio]

I observed test results where this change was made to a dev fork; the "right thing" happened, and nothing else broke.