fix: make storage variable internal due to existing getter

[nadir-akhtar]

Motivation:

avsConfig is marked public, but the getter getAVSConfig also retrieves the storage variable. Making the storage variable public automatically produces a getter. As such, currently two getters exist for the same storage variable.

Modifications:

• Changed the storage variable from public to internal

Result:

• Cheaper deployments
• More legible getters