[Bug]: Missing Spanner PG Dialect test for live replication

### Related Template(s)

datastream-to-spanner

### Template Version

v2

### What happened?

The Live replication template is currently missing integration tests to validate datatype conversions to the Spanner PostgreSQL (PG) dialect.

While the Bulk and Reverse replication templates already include these equivalent tests, they still need to be added to the Live template. This issue tracks the implementation of these missing tests.

### Relevant log output

```shell

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