java - Import an old LibGDX / Eclipse project to Android Studio -

i'm trying import old libgdx android game android studio. last worked on using eclipse around year , half ago, , project looks this:

where androidgame-core game logic , androidgame-android contains android components androidmanifest , resources. both androidgame-android , androidgame-core have build.gradle file.

i imported android studio in way: file -> new -> import project selected directory containing 3 folders above.

this imported both androidgame-core , androidgame-android android studio required - however, red , can't find build.gradle file or assets folder (containing things such sprites).

androidstudio giving me message "this project not use gradle build system. recommend migrate using gradle build system."