Simplify localStorage null check for better readability

[Chy-Zaber-Bin-Zahid]

Before:

!(localStorage.getItem(LOCAL_STORAGE_KEY_NAME) === null)

After:

localStorage.getItem(LOCAL_STORAGE_KEY_NAME) !== null

Changes:

• Replaced negated equality check with direct positive comparison
• Improved code readability by eliminating double negation
• Made the intent more explicit and easier to understand

This follows clean code best practices by preferring positive conditionals over negated ones