Split size error on `amazon_us_reviews` / `PC_v1_00` dataset
Follow-up: I have confirmed there are no duplicate lines via `sort amazon_reviews_us_PC_v1_00.tsv | uniq -cd` after extracting the raw file. Hi @trentonstrong, thanks for reporting!

I confirm that loading this dataset configuration throws a `NonMatchingSplitsSizesError`:
```
NonMatchingSplitsSizesError: [{'expected': SplitInfo(name='train', num_bytes=350242049, num_examples=785730, dataset_name='amazon_us_reviews'), 'recorded': SplitInfo(name='train', num_bytes=3982712078, num_examples=6908554, dataset_name='amazon_us_reviews')}]
```

Also thank you for your offer to fix this. You can find information about how to update the metadata JSON file here: https://github.com/huggingface/datasets/blob/master/ADD_NEW_DATASET.md#automatically-add-code-metadata
```shell
datasets-cli test datasets/amazon_us_reviews --save_infos --all_configs
```
Please, feel free to open a PR with this fix. And do not hesitate to ping me if you need any help. No sweat. Will get it patched up ASAP.
## Describe the bug
When downloading this subset as of 3-28-2022 you will encounter a split size error after the dataset is extracted. The extracted dataset has roughly ~6m rows while the split expects <1m. 

Upon digging a little deeper, I downloaded the raw files from `https://s3.amazonaws.com/amazon-reviews-pds/tsv/amazon_reviews_us_PC_v1_00.tsv.gz` and extracted them. A line count via `wc -l` confirms the ~6m number that we see and the data looks valid at a glance (I did not check for duplicate rows). My guess is this file has either been updated in place or there is a bug in the dataset metadata.

Happy to submit a PR and fix this up if turns out to be a metadata issue but wanted to get some other :eyes: on it first.

## Steps to reproduce the bug
```python
load_dataset('amazon_us_reviews', 'PC_v1_00')
```

## Expected results
Dataset is downloaded and extracted successfully.

## Actual results
An split size exception is thrown.

## Environment info
<!-- You can run the command `datasets-cli env` and copy-and-paste its output below. -->
- `datasets` version: 2.0.0
- Platform: Linux-5.10.16.3-microsoft-standard-WSL2-x86_64-with-glibc2.29
- Python version: 3.8.10
- PyArrow version: 7.0.0
- Pandas version: 1.4.1
