[SPARK-3921] Fix CoarseGrainedExecutorBackend's arguments for Standalone mode

The goal of this patch is to fix the swapped arguments in standalone mode, which was caused by  https://github.com/apache/spark/commit/79e45c9323455a51f25ed9acd0edd8682b4bbb88#diff-79391110e9f26657e415aa169a004998R153.

More details can be found in the JIRA: [SPARK-3921](https://issues.apache.org/jira/browse/SPARK-3921)

Tested in Standalone mode, but not in Mesos.

Author: Aaron Davidson <aaron@databricks.com>

Closes #2779 from aarondav/fix-standalone and squashes the following commits:

725227a [Aaron Davidson] Fix ExecutorRunnerTest
9d703fe [Aaron Davidson] [SPARK-3921] Fix CoarseGrainedExecutorBackend's arguments for Standalone mode