Is NDK needed for flutter?

It depends on the project type . The dialog you showed appears for an Android project but not for a Flutter one for me. With a Flutter app, the accepted answer was the one that helped me, too: installing the required NDK. I think this is the correct answer for the general use of the NDK.

The Android NDK is a companion tool to the Android SDK that lets you build performance-critical portions of your apps in native code . It provides headers and libraries that allow you to build activities, handle user input, use hardware sensors, access application resources, and more, when programming in C or C++.25 Nis 2017

The Native Development Kit (NDK) is a set of tools that allows you to use C and C++ code with Android, and provides platform libraries you can use to manage native activities and access physical device components , such as sensors and touch input.30 Eyl 2020

The Android NDK is a companion tool to the Android SDK that lets you build performance-critical portions of your apps in native code . It provides headers and libraries that allow you to build activities, handle user input, use hardware sensors, access application resources, and more, when programming in C or C++.25 Nis 2017

The Native Development Kit (NDK) is a set of tools that allows you to use C and C++ code with Android, and provides platform libraries you can use to manage native activities and access physical device components , such as sensors and touch input.30 Eyl 2020