fix typos in training apis (#13908)
### Description
This PR fixes some typos in the training apis.
We need to add more tests and make sure they are all run on the CIs to
capture such issues. These changes are out of scope of this PR.
### Motivation and Context
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Co-authored-by: Ashwini Khade <askhade@microsoft.com@orttrainingdev8.d32nl1ml4oruzj4qz3bqlggovf.px.internal.cloudapp.net>
