fix(core): assign the correct keys for Apple and Amazon providers

[israx]

Description of changes

Currently there is a key miss match present in the Amazon and Apple social providers generated by amplifyOutputs. This PR matches the returned keys in the parseAmplifyOutputs helper.

Issue #, if available

Description of how you validated changes

Checklist

• [x] PR description included
• [x] yarn test passes
• [x] Tests are changed or added
• [ ] Relevant documentation is changed or added (and PR referenced)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.