[MINOR][DOCS] Update build descriptions and commands

## What changes were proposed in this pull request?

This PR updates Scala and Hadoop versions in the build description and commands in `Building Spark` documents.

## How was this patch tested?

N/A

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #11838 from dongjoon-hyun/fix_doc_building_spark.