PARQUET-3261: Fix integer overflow in CapacityByteArrayOutputStream

[yadavay-amzn]

What changes were made?

Fix integer overflow in CapacityByteArrayOutputStream.addSlab() that causes ArithmeticException when writing large ARRAY<STRING> columns (issue #3261).

Root cause (identified by @Kimahriman)

The overflow check in addSlab() used bytesUsed to detect overflow, but bytesUsed is not updated until after addSlab() returns in write(). Additionally, nextSlabSize can be larger than minimumSize (due to the doubling strategy), so checking only bytesUsed + minimumSize was insufficient.

This meant bytesAllocated = Math.addExact(this.bytesAllocated, nextSlabSize) could overflow without being caught by the guard, throwing an uncaught ArithmeticException instead of the intended OutOfMemoryError.

Fix

1. Use bytesAllocated instead of bytesUsed for the overflow check — bytesAllocated is always up to date when addSlab() is called.
2. Cap nextSlabSize when it would cause bytesAllocated to overflow Integer.MAX_VALUE, preventing the uncaught ArithmeticException on the Math.addExact call.

Tests

Added TestCapacityByteArrayOutputStreamOverflow with two tests:

• Verifies that slab allocation near Integer.MAX_VALUE succeeds (previously threw ArithmeticException)
• Verifies that a true overflow still throws OutOfMemoryError as intended

[steveloughran]

LGTM