Put awx analytics logs also in the task system logger

Errors/warnings when gathering analytics are about 50/50 split between
the gathering code in analytics and the task code that calls it, so
they should be in the same place for debugging sanity.

awx/settings/defaults.py

@@ -1001,7 +1001,7 @@ LOGGING = {
             'level': 'INFO',  # very verbose debug-level logs
         },
         'awx.analytics': {
-            'handlers': ['external_logger'],
+            'handlers': ['task_system', 'external_logger'],
             'level': 'INFO',
             'propagate': False
         },