We use the preview from onImageCaptured. We take two images back-to back, one without flash, one with flash. We set the capture destination to a nonsensical location like "/dummy.jpg" because we do not care about the full-size image. Under 5.5.0 and previous versions we were able to request the capture and get both previews as expected, then get the failed handler. Under 5.5.1, in Android only, we no longer get the second preview, it just goes straight to the onCaptureFailed.
Building against 5.5.0 we get the behavior we expect.

5.5.0:

// request capture 1
onImageCaptured(preview) // image://camera/preview_1
onCaptureFailed() 
// request capture 2
onImageCaptured(preview) // image://camera/preview_2
onCaptureFailed()

5.5.1:

// request capture 1
onImageCaptured(preview) // image://camera/preview_1
onCaptureFailed() 
// request capture 2
onCaptureFailed()