Cannot Become Any Account for account whose full name is empty string

If an account's full name is an empty string, it will not be selectable
on the development Become Any Account login screen.

Fix the account list population to also check if the full name is empty
before using it.  Thus, an account whose full name is empty will be
listed with either the preferred email address or ID.

Change-Id: Ica7b42def9c3816c233c03d1e2ca4b6889513fa9
1 file changed