RCCA-8574: Handle default value as null for complex data types

[skaushikcflt]

Problem

Complex schema type such as array, struct, maps having default value as null is causing a NPE

Solution

When a complex schema type is received, we further expand it to get to native data types by typecasting the value. Before typecasting the value, we should check for the null value and return if a null value is found

Does this solution apply anywhere else?

• [x] yes
• [ ] no

If yes, where?

Test Strategy

Testing done:

• [x] Unit tests
• [ ] Integration tests
• [ ] System tests
• [x] Manual tests

Release Plan

[venkatteki]

@skaushikcflt General practice is not to do commit --amend

[skaushikcflt]

Will raise a new PR without quickstart changes.