Fix installation script to skip Audit DB password check if audit source is SOLR

Problem Statement: Installation script tries to do validation on Audit DB password even if audit source is set to SOLR

Expected Behavior: On Ranger installation even if user chooses to not use Audit to DB, install script calls password validation method to validate password and installation fails if audit db password is not provided.

Actual Behavior: If user chooses to not use audit to DB as audit source then installation script should not do any audit db related password validation and audit to DB related properties should not be updated.

Steps to Reproduce:

• Select audit source type as solr
• Give invalid/blank password as Audit to DB password
• Run the setup script, the script will fail