Select correct ObjectInspector based on Hive version on classpath

[marton-bod]

To fix #1630, the ObjectInspector selection logic needs to depend on checking the presence of Hive3 classes on the classpath.
cc @rdblue @massdosage @pvary - thanks for checking!

[massdosage]

I just tested this on our cluster and it fixes the issue I reported.

[rdblue]

It seems like it would be a bit easier to read if you didn't wrap the DynMethods call and instead just swapped out the class:

private static final TIMESTAMP_INSPECTOR_CLASS = MetastoreUtil.hive3PresentOnClasspath() ?
    "org.apache.iceberg.mr.hive.serde.objectinspector.IcebergTimestampObjectInspector" :
    "org.apache.iceberg.mr.hive.serde.objectinspector.IcebergTimestampObjectInspectorHive3";
private static final ObjectInspector TIMESTAMP_INSPECTOR = DynMethods.builder("get")
    .impl(TIMESTAMP_INSPECTOR_CLASS, boolean.class)
    .buildStatic()
    .invoke(false);

That way you don't need all of the inline array literals.

[marton-bod]

yep...much simpler, thanks:)
changed it

[rdblue]

Thanks for the fix!