Allow specifying all flavor types

In I1b653020acf4b5acb510ba4a092f854815e36a87, support was added to
allow operators to specify the flavor they wished to use for control
and compute nodes, but this missed two other types that operators may
wish to change, namely block storage and swift storage.

Change-Id: I8a009bc1feaa34a98d20f5c18ea29145c00d428c
Merge "Allow specifying all flavor types"