Fix issue where the themed submission page would crash

[artlowel]

References

• Fixes issue introduced by Make all non-admin page-level components themeable #1042

Description

After #1042 was merged the submission page would crash when creating a new submission, due to a mistake in the component name in ThemedSubmissionSubmitComponent

Instructions for Reviewers

Using this PR the submission should no longer crash, with or without a theme.

Checklist

This checklist provides a reminder of what we are going to look for when reviewing your PR. You need not complete this checklist prior to creating your PR (draft PRs are always welcome). If you are unsure about an item in the checklist, don't hesitate to ask. We're here to help!

• My PR is small in size (e.g. less than 1,000 lines of code, not including comments & specs/tests), or I have provided reasons as to why that's not possible.
• My PR passes TSLint validation using yarn run lint
• My PR doesn't introduce circular dependencies
• My PR includes TypeDoc comments for all new (or modified) public methods and classes. It also includes TypeDoc for large or complex private methods.
• My PR passes all specs/tests and includes new/updated specs or tests based on the Code Testing Guide.
• If my PR includes new, third-party dependencies (in package.json), I've made sure their licenses align with the DSpace BSD License based on the Licensing of Contributions documentation.

[tdonohue]

👍 Thanks @artlowel ! This looks correct & I also tested it locally and it fixes the issue.