fix(jira) Make post-install simpler (#10626)
fix(jira) Make post-install simpler (#10626)

Customers have been getting confused about how to get jira setup as
required steps are buried deep inside jira addon configuration. By using
a `postInstallPage` we can make it clearer to the user that there is
more for them to do.

Fixes APP-785
beeftornado/sentry,mvaled/sentry,mvaled/sentry,beeftornado/sentry,beeftornado/sentry,mvaled/sentry,mvaled/sentry,mvaled/sentry,mvaled/sentry