Adding support for RsaKey for self-attestation

[abahety]

• While testing in production, we found that windows devices with Hello support are generating self-attestation format with Rsa crypto and the current code is not supporting that
• Raising this PR to expand the coverage and prevent failures

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[abahety]

@googlebot I signed it!

[abahety]

I am part of eBay group which has CLA already signed. https://groups.google.com/a/ebay.com/forum/?hl=en#!members/dl-ebay-tesseract-dev