[Prioritized] JSON normalization is not consistent between playback and record

When recording, we attempt to normalize the JSON of the request body as long as it is a [text content type](https://github.com/Azure/azure-sdk-tools/blob/main/tools/test-proxy/Azure.Sdk.Tools.TestProxy/Common/RecordEntry.cs#L202). When matching in playback, we only normalize the request if the content type [contains "json"](https://github.com/Azure/azure-sdk-tools/blob/main/tools/test-proxy/Azure.Sdk.Tools.TestProxy/Common/RecordEntry.cs#L129). This can result in playback mismatches when the actual request is valid JSON, but the content type is some other text type. Should be fairly rare in practice but would be good to fix this to be consistent.