[image_picker][Android]: return without any processing if extension gif

[hyeokeunmun]

When picking a GIF image with maxWidth/maxHeight on Android, there's an issue where the animation of the file gets removed.
It seems necessary to add proper resizing logic for GIF files, but for now, I've added straightforward logic to return the original file if it's a GIF file.

Fixes #144546 related #34134

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[stuartmorgan-g]

Thanks for the contribution, but this is not a change we would accept. Please see discussion here and here, as well as later discussion in that PR.