Fix return for Kafka Avro deserializer

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.

Project coverage is 41.22%. Comparing base (66f4322) to head (a8e99f0). Report is 3 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1671 +/- ## ============================================ - Coverage 41.23% 41.22% -0.01% + Complexity 2928 2925 -3 ============================================ Files 763 763 Lines 44393 44391 -2 Branches 4754 4754 ============================================ - Hits 18305 18300 -5 Misses 24545 24545 - Partials 1543 1546 +3 ``` | [Components](https://app.codecov.io/gh/GoogleCloudPlatform/DataflowTemplates/pull/1671/components?src=pr&el=components&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=GoogleCloudPlatform) | Coverage Δ | | |---|---|---| | [spanner-templates](https://app.codecov.io/gh/GoogleCloudPlatform/DataflowTemplates/pull/1671/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=GoogleCloudPlatform) | `61.33% <ø> (-0.05%)` | :arrow_down: | | [spanner-import-export](https://app.codecov.io/gh/GoogleCloudPlatform/DataflowTemplates/pull/1671/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=GoogleCloudPlatform) | `64.34% <ø> (-0.11%)` | :arrow_down: | | [spanner-live-forward-migration](https://app.codecov.io/gh/GoogleCloudPlatform/DataflowTemplates/pull/1671/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=GoogleCloudPlatform) | `73.88% <ø> (ø)` | | | [spanner-live-reverse-replication](https://app.codecov.io/gh/GoogleCloudPlatform/DataflowTemplates/pull/1671/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=GoogleCloudPlatform) | `49.66% <ø> (ø)` | | | [spanner-bulk-migration](https://app.codecov.io/gh/GoogleCloudPlatform/DataflowTemplates/pull/1671/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=GoogleCloudPlatform) | `82.07% <ø> (ø)` | | | [Files](https://app.codecov.io/gh/GoogleCloudPlatform/DataflowTemplates/pull/1671?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=GoogleCloudPlatform) | Coverage Δ | | |---|---|---| | [...s/KafkaRecordToGenericRecordFailsafeElementFn.java](https://app.codecov.io/gh/GoogleCloudPlatform/DataflowTemplates/pull/1671?src=pr&el=tree&filepath=v2%2Fkafka-common%2Fsrc%2Fmain%2Fjava%2Fcom%2Fgoogle%2Fcloud%2Fteleport%2Fv2%2Fkafka%2Ftransforms%2FKafkaRecordToGenericRecordFailsafeElementFn.java&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=GoogleCloudPlatform#diff-djIva2Fma2EtY29tbW9uL3NyYy9tYWluL2phdmEvY29tL2dvb2dsZS9jbG91ZC90ZWxlcG9ydC92Mi9rYWZrYS90cmFuc2Zvcm1zL0thZmthUmVjb3JkVG9HZW5lcmljUmVjb3JkRmFpbHNhZmVFbGVtZW50Rm4uamF2YQ==) | `0.00% <0.00%> (ø)` | | ... and [2 files with indirect coverage changes](https://app.codecov.io/gh/GoogleCloudPlatform/DataflowTemplates/pull/1671/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=GoogleCloudPlatform)

[AnandInguva]

I will merge this with https://github.com/GoogleCloudPlatform/DataflowTemplates/pull/1649 and we can submit that one containing both changes (just to get both in faster)