Check the length of flavor name in "flavor-create"

Fixes bug 1102280
The length of flavor name is defined 255 charaters in database.
But flavor name can be more than 255 characters when a flavor
is created. This patch adds the length check of flavor name.

Change-Id: If9db879e5f6340594b215b057a29d03c6fef1503
Merge "Check the length of flavor name in "flavor-create""