Is donation to building a new masjid in community considered as sadaqa jariyah?

So yes, this is a form of Sadaqah Jariyah. Sadaqah Jariyah means something which will continue to benefit others. So for example, contributing to building a masjid that will continue. Whoever prays in there, whoever does wudu in there, whoever does the adhan in there, whoever breaks their fast in that masjid, whoever prays tahajjud in that masjid and so on, you will be getting part of the reward because you've contributed to that masjid and it's ongoing. It's going to continue even when you have passed away as long as the masjid is there. Other examples are, let's say, building a water well. Whoever drinks and uses the water from that to do their wudu or to ensure their bodies are healthy or to enable them to pray and so on, then you are going to be getting that reward as well inshaAllah.