Parquet: Add tests for disabling statistics on multiple columns

[LouisDeconinck]

Summary

Adds test coverage in TestParquet for disabling Parquet column statistics via write.parquet.stats-enabled.column.<COLUMN_NAME> on multiple columns at once, the scenario reported in #15347.

The multi-column disable path already works correctly on main (as confirmed in the issue discussion and in the earlier attempts), so this PR adds regression coverage only — no production code changes.

A shared writeAndAssertColumnStatistics helper writes records with the given table properties and asserts per-column statistics presence in the Parquet footer. All of the tests share one constant schema and express expectations as a column name to statistics-presence map, per the review feedback on #17365:

• testColumnStatisticsDefault — no per-column properties; all columns write statistics
• testColumnStatisticsEnabled — existing test, refactored onto the shared schema and helper (one column enabled, one disabled, one unconfigured)
• testMultipleColumnsStatisticsDisabled — two columns disabled; both omit statistics while the unconfigured third column still writes them (the reported Disabling statistics across multiple columns #15347 scenario)
• testAllColumnsStatisticsDisabled — statistics disabled on every column in the schema

Fixes #15347

Test plan

• ./gradlew :iceberg-parquet:test --tests 'org.apache.iceberg.parquet.TestParquet' — 26 tests, all pass
• ./gradlew :iceberg-parquet:spotlessCheck — clean

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AI Disclosure

• Model: [unknown - human to fill in]
• Platform/Tool: Devin
• Human Oversight: unreviewed
• Prompt Summary: Investigate Disabling statistics across multiple columns #15347 and contribute a fix consistent with maintainer feedback on prior attempts

[yangshangqing95]

LGTM.
Nit, non-blocking: could we remove the test prefix from the newly added test method names?

[LouisDeconinck]

Done — the three new test methods now drop the test prefix (columnStatisticsDefault, multipleColumnsStatisticsDisabled, allColumnsStatisticsDisabled), matching the project convention. The pre-existing testColumnStatisticsEnabled keeps its name.

[LouisDeconinck]

Done — dropped the test prefix from the newly added test methods (columnStatisticsDefault, multipleColumnsStatisticsDisabled, allColumnsStatisticsDisabled).

[LouisDeconinck]

Thanks! Dropped the test prefix from the new test method names (columnStatisticsDefault, multipleColumnsStatisticsDisabled, allColumnsStatisticsDisabled).