Allow users to set the disk type for the Cloud SQL instance, similar to how you can do this for the Forseti server.

Moved this issue from the main Forseti repo: forseti-security/forseti-security#2591.

At the moment the script just replaces "Null separator" (\x00) to space (' ').

But the chunk has more interesting information:

+--------------------+------------------------------------+
| Keyword            | 1-79 bytes (character string)      |
| Null separator     | 1 byte                             |
| Compression flag   | 1 byte                             |
| Compression me