Ensure SessionAttribute defaults to same behavior as 1.2

[twsouthwick]

As part of expanding the session support to enable per request changing the session behavior in #399, it appears that the default SessionAttribute was changed to have a different default value.

Fixes #455

[twsouthwick]

@joperezr not sure who I should be adding for reviews now, but once this is merged, we should push a v1.3.1 to fix this and a couple other regressions that have been fixed

[joperezr]

We haven't really defined who will be the dev working on this repo yet, but I'm happy to take a look at this one. Seems like it was a regression (reported by the community) and fix seems trivial and tested, so I'm supportive of this. Happy to ship a new version with this, but do note that main is currently 1.4.0 as opposed to 1.3.1. Do we care about it being 1.3.1?

[twsouthwick]

Following semantic versioning would put us at 1.3.1, but 1.4.0 is fine if it will cause problems to change the version

[joperezr]

It shouldn't it is just a matter of one more update in Versions.props. Or alternatively creating a release/3.1 branch from the commit that released 1.3.0 and cherry-picking this PR there. Either option would be fine.

[twsouthwick]

It would be great to just take all 4 commits since 1.3 and release it as 1.3.1 - however that needs to be done I'll leave up to you :)