[home] Mock ExponentKernel.sdkVersions correctly in UserSessions test
[home] Mock ExponentKernel.sdkVersions correctly in UserSessions test

We don't want to overwrite the ExponentKernel mock that is already provided -- assign to the one that's already there.

exponentjs/exponent,exponentjs/exponent,exponent/exponent,exponent/exponent,exponentjs/exponent,exponentjs/exponent,exponent/exponent,exponent/exponent,exponent/exponent,exponentjs/exponent,exponent/exponent,exponent/exponent,exponent/exponent,exponentjs/exponent,exponentjs/exponent,exponent/exponent,exponentjs/exponent,exponentjs/exponent