[Extensions] Fix regression, extensions not being registered on Tizen and Android

RegisterInternalExtensionsInServer should have been renamed for Tizen and
Android and not only for desktop. The extensions were not being registered
because of that for these platforms.

Thanks to Jesus Sanchez-Palencia for pointing the directions.
Merge pull request #1189 from tmpsantos/server_fix

[Extensions] Fix regression, extensions not being registered on Tizen and Android