Messaging server prompts should not accept empty password

[miyamotoh]

ManageIQ started requiring Messaging/Kafka in recent releases. In appliance_console > 4. Configure Application, you can configure it as part of initial setup by answering a series of questions/prompts. For Messaging part, it'd ask;

1. if I want to un-configure first
2. hostname/IP (current hostname provided as default)
3. Keystore username ("admin" provided as default)
4. Keystore password (no default, naturally)
5. if I want to a dedicated persistent volume

It is easy to just hit ENTER 3 times for the Q2-4, though "empty password" would result in below error. It should not move onto Q5, if password entered was empty.

Proceed? (Y/N): Y
Checking connectivity to testvm1.localdomain ...
Succeeded.
Create Jaas Config
Create Client Properties
Create Logs Directory
Configure Firewall
Configure Keystore
keytool error: java.lang.Exception: Keystore file does not exist: /opt/kafka/config/keystore/keystore.jks

Similarly, I've heard Kafka doesn't like localhost as hostname, and thus for Q2, if something like localhost or maybe what'd resolve to 127.0.0.1 is entered, it should perhaps be rejected as well.

[kbrock]

@agrare there is a regex (and description) for prompts. That can probably get this.
You self-assigned, so leaving in your court.
But ping if you want me to do it.

[agrare]

@kbrock we do this double-prompt for a new password and check that the password isn't empty in the internal_database_configuration class so I moved that into a common place, would love your feedback if you get a chance