[SPARK-3912][Streaming] Fixed flakyFlumeStreamSuite

@harishreedharan @pwendell
See JIRA for diagnosis of the problem
https://issues.apache.org/jira/browse/SPARK-3912

The solution was to reimplement it.
1. Find a free port (by binding and releasing a server-scoket), and then use that port
2. Remove thread.sleep()s, instead repeatedly try to create a sender and send data and check whether data was sent. Use eventually() to minimize waiting time.
3. Check whether all the data was received, without caring about batches.

Author: Tathagata Das <tathagata.das1565@gmail.com>

Closes #2773 from tdas/flume-test-fix and squashes the following commits:

93cd7f6 [Tathagata Das] Reimplimented FlumeStreamSuite to be more robust.
[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