Apply bettter code implementation to avoid Source Formatter Complain

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 2.1.2
• Fix Version/s: 2.1.2
• Component/s: Digital Merchandise Management → Price Lists
• Labels: None
• Git Pull Request: https://github.com/marco-leo/liferay-portal-ee/pull/1115

private variables should be final as possible - SF fixes class member varables to final if variables are not altered in methods.

To avoid collisions with SF variables should be initialized in constructor...