Is the song hello dolly by louis armstrong an aaba form or 12-bar blues?

It is not a blues, nor it is an AABA form. The first eight bars in Louis Armstrong's version are in Bb, the second group eight start in C minor but modulate back toward Bb for the third group of eight, and the fourth group of eight starts in G minor (relative to Bb, but the D7 at the end of the third eight suggests G harmonic minor) and through a couple of secondary dominants until ultimately resolving to Bb. I'd label it ABAC or ABA with a coda.