BatchGetItem has two limit, up to 100 items at once and up to 1MB data at once, whichever comes first. The point of this test is to test fetching up to 1MB of data.

Previously this test case was wrong, because each individual record cannot be larger than 64KB. Rudy FakeDynamo doesn't check that, but DynamoDB Local does, so the test case fails to initialize.

With this change, DynamoDB Local returns 16 items at a time, which is expected, however, it returns less unprocessed keys than expected so this test case still fails now.