AMBARI-25865: Fix an unit test failure on ambari-metrics-host-monitoring

[sekikn]

What changes were proposed in this pull request?

Currently, we have a unit test failure in ambari-metrics-host-monitoring, as follows:

$ mvn clean test -f ambari-metrics-host-monitoring/pom.xml

...

[INFO] --- exec-maven-plugin:1.2.1:exec (python-test) @ ambari-metrics-host-monitoring ---
Running tests
Traceback (most recent call last):
  File "unitTests.py", line 137, in <module>
    sys.exit(main())
  File "unitTests.py", line 106, in main
    modules]
  File "/usr/lib/python2.7/unittest/loader.py", line 91, in loadTestsFromName
    module = __import__('.'.join(parts_copy))
  File "/home/sekikn/repos/ambari-metrics/ambari-metrics-host-monitoring/src/test/python/core/TestHostInfo.py", line 24, in <module>
    from host_info import HostInfo
  File "/home/sekikn/repos/ambari-metrics/ambari-metrics-host-monitoring/src/main/python/core/host_info.py", line 25, in <module>
    import psutil
ImportError: No module named psutil
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  1.402 s
[INFO] Finished at: 2023-02-24T14:47:38+09:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.2.1:exec (python-test) on project ambari-metrics-host-monitoring: Command execution failed.: Process exited with an error: 1 (Exit value: 1) -> [Help 1]

This is because src/main/python/core/__init__.py assumes the psutil package is under src/main/python/psutil/build, but pom.xml uses another directory to build it.

In addition, the core package of ambari-metrics-host-monitoring should be loaded before TestHostInfo.py so that the psutil package is loaded in advance.

How was this patch tested?

Ran mvn clean test -f ambari-metrics-host-monitoring/pom.xml with this PR locally, as follows:

$ mvn clean test -f ambari-metrics-host-monitoring/pom.xml

...

Ran 19 tests in 1.022s

OK
----------------------------------------------------------------------
Total run:19
Total errors:0
Total failures:0
OK

...

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  2.675 s
[INFO] Finished at: 2023-02-24T15:02:03+09:00
[INFO] ------------------------------------------------------------------------

[kevinw66]

+1 lGTM, thanks @sekikn