Memory question regarding textures android

Hi, i've got a texture with two formats a TGA and a PNG. TGA = 3.2mb PNG = 1.6mb i was wondering when building out to android do i choose the png because it will lower the apk package size compared to tga or does it not matter at all? (i've actually got lots of tga textures so before converting them to pngs was wondering if it will lower the package size)