[SPARK-16388][SQL] Remove spark.sql.nativeView and spark.sql.nativeView.canonical config

## What changes were proposed in this pull request?
These two configs should always be true after Spark 2.0. This patch removes them from the config list. Note that ideally this should've gone into branch-2.0, but due to the timing of the release we should only merge this in master for Spark 2.1.

## How was this patch tested?
Updated test cases.

Author: Reynold Xin <rxin@databricks.com>

Closes #14061 from rxin/SPARK-16388.