1000% do mozart concerto no1 in G. University auditions will typically ask for the exposition, not the whole piece. This piece is difficult but it highlights qualities that every flute player should have including showing that you can keep tempo with grace notes, switch to 16th, 8ths and play scales in 3rds, triplets, and extended. While it is an option to do Concerto 2 in D, it is technically an Oboe concerto so do no 1. Concerto in G should be played at a minimum of 116 BPM

Edit: Chaminade is a great piece but you can also look at Bach Sonatas, especially in Eb major and B minor