Default file access costs are reversed

Currently they are defined as:

 cost:
    currencyCode: USD
    perCpu: 0.126
    storageAtRest: 0.0135
    storageReads: 0.0485
    storageWrites: 0.0038

The read cost should be lower than the write cost.  They should all be adjusted to match something like premium blob storage on azure and the cpu costs for a large (e.g. 64 cpu) instance so they are more representative.