Enable flash for all sites

[Mattches]

@matteopa,
Actually, this is not possible to do with Flash specifically.
See my reply here:

Flash Player in Chrome

@PatrickR, This is not possible – Flash is susceptible to security vulnerabilities and as such, is restricted to only being granted per-site access to avoid bad actors taking advantage of the “always allow” permission. Additionally, for what it’s worth, Flash is “on its way out” – set to be fully depreciated in 2020. We apologize for the inconvenience but hope you understand that user safety and security are paramount in situations like this.