Fix RawTripTestPayload testcases to use the same payload for table config

It was seen that for RawTripTestPayload currently OverwriteWithLatestAvroPayload is set in the table config payload. We should fix the use cases to use RawTripTestPayload itself in the table config payload.
We should also add validation that payload class is same for custom payload merger here [https://github.com/lokeshj1703/hudi/blob/9c6f5306abd71279f5eb32ab5d6ff1bd56533b42/hudi-common/src/main/java/org/apache/hudi/common/table/read/BufferedRecordMergerFactory.java#L101]

refer: [https://github.com/apache/hudi/pull/13600#discussion_r2253901023]

## JIRA info

- Link: https://issues.apache.org/jira/browse/HUDI-9689
- Type: Improvement

Start with the RawTripTestPayload test cases and the custom payload merger handling in hudi-common/src/main/java/org/apache/hudi/common/table/read/BufferedRecordMergerFactory.java around the referenced line. Check where OverwriteWithLatestAvroPayload is used in the table configuration and where payload classes are selected. Done means the table configuration uses RawTripTestPayload and validation rejects a different custom payload class.

Written by the indexing model from the issue text.