fix: fix test for KIP-307 final PR

[bbejeck]

Description

The fifth and final PR for KIP-307 is getting merged today. This PR adds the following overload KGoupedTable.aggregate(Initializer, Aggregator, Aggregator, Named).

This causes an error with the SchemaKGroupedTableTest when executing mockKGroupedTable.aggregate(any(), any(), any(), any())) method. The compiler can't disambiguate the 4th argument, as it's either a Materialized or a Named object. This PR fixes the test.

Update this PR build is passing now and can be merged once approved.

Testing done

I updated the test and ran the entire KSQL test suite, all tests passed.

Reviewer checklist

• Ensure docs are updated if necessary. (eg. if a user visible feature is being added or changed).
• Ensure relevant issues are linked (description should include text like "Fixes #")

[rodesai]

Would be cleaner to do any(Materialized.class).

[bbejeck]

Ack. I updated one instance of (Materialized)any() to any(Materialized.class) on line 314.

But changing this line to use any(Materialized.class) caused NullPointerExceptions in the test.

The reason for this from what I can see is that this function returns null instead of a Materialized instance in the test:
https://github.com/confluentinc/ksql/blob/master/ksql-engine/src/main/java/io/confluent/ksql/structured/SchemaKGroupedTable.java#L154-L158

By changing the mock to expect a Materialized.class explicitly I think the mock returns null instead of the KTable instance when this is called ( https://github.com/confluentinc/ksql/blob/master/ksql-engine/src/main/java/io/confluent/ksql/structured/SchemaKGroupedTable.java#L160-L164)

I'm thinking this is ok as is or we could add something like when(materializedFactory.create(any(), any(), any())).thenReturn(materialized); in the init() method. WDYT?

[bbejeck]

@rodesai updated per comments

[bbejeck]

Rebased and updated for additional test

[rodesai]

LGTM