This fixes handling of values bigger than 2GiB for the following command-line flags:
- -storage.minFreeDiskSpaceBytes
- -remoteWrite.maxDiskUsagePerURL
Arch 386 is a 32-bit architecture and interprets int type for numbers as an explicit int32,
whereas on most modern CPUs int is implicitly an int64. This makes tests to fail with
`int overflow` error.