Sadly there's no setting to exclude certain file types, so you only recourse here is to reach to Google Support and tell them about your problem.
HEIC shouldn't be blocked, since it's just an image format, just like GIF, JPG and PNG.
@Kristal any chance you can get the message over to the Chrome team?
HEIC should be included in this exemption list.
https://source.chromium.org/chromium/chromium/src/+/main:components/safe_browsing/content/resources/...
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