parquet-avro logical type support broke ability to use avro reflection with generics.

Impacts 1.9.0 and 1.8.2.

Assuming the fieldClass is a concrete class (which it is for all of the logical types) is an incorrect assumption when generics are used.

Statistics {
T field1
T field2
}

SetStatistics extends Statistics> {}

Solution is to check if the fieldClass is abstract/interface/raw object.

**Reporter**: [Evan McClain](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=aeroevan) / @aeroevan
**Assignee**: [Evan McClain](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=aeroevan) / @aeroevan
#### Original Issue Attachments:
- [0001-Do-not-pass-knownClass-if-it-is-abstract-interface.patch](https://issues.apache.org/jira/secure/attachment/12850491/0001-Do-not-pass-knownClass-if-it-is-abstract-interface.patch)

_{**Note**: *This issue was originally created as [PARQUET-856](https://issues.apache.org/jira/browse/PARQUET-856). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*}

Usa gli esempi Statistics e SetStatistics extends Statistics> per riprodurre il problema di reflection di Avro. Esamina la gestione dei tipi logici di parquet-avro intorno a fieldClass e confrontala con la patch allegata; il lavoro è completato quando la reflection generica funziona senza passare una classe astratta, di interfaccia o Object grezzo come classe nota.

Scritto dal modello di indicizzazione a partire dal testo della issue.