[Bug report] Progress only updates when the download is complete

[cambo2015]

Describe the bug
When downloading a translation language model and calling .observe on the Progress object using .fractionCompleted, it only updates when the download is finished instead of incrementally updating; the result, updated one time, is 1.0. Thank you in advance.

To Reproduce
Example Steps to reproduce the behavior in the sample app:

• open xCode,
• install pod 'GoogleMLKit/Translate', '3.2.0'
• use the following below:
  If applicable, please include code snippet and sample input(image, video, text, etc)

   func downloadModel(language:TranslateLanguage){
        let model = TranslateRemoteModel.translateRemoteModel(language: language)
        let progress =  ModelManager.modelManager().download(
            model,
            conditions: ModelDownloadConditions(
                allowsCellularAccess: true,
                allowsBackgroundDownloading: true
                
            )
        )
        progress.observe(\.fractionCompleted){ progress, _  in
            print(progress.fractionCompleted) // only prints 1 .0 only 1 time. Need it to print multiple times and give percentage.
            self.downloadProgressHandler!(progress.fractionCompleted,language) // a callback within the class that will go to the Swift UI
        }
    }

Expected behavior
Expect

SDK Info:

• SDK Name & Version 'GoogleMLKit/Translate', '3.2.0'

Smartphone:

• Device/Simulator: IOS simulator, physical iPhone 11
• Device/Simulator OS: iPhone 15 iOS 17.3

Development Environment:
(For Android issue feel free to skip this section)

• IDE Eversion: Xcode 15.2
• Laptop/Desktop: MacBook Pro m1 2020
• Laptop/Desktop OS/version: Sonoma 14.3