Update system metrics to work with new metrics imports (#1075)

Author: aabmass

.github/workflows/test.yml

@@ -6,7 +6,7 @@ on:
     - 'release/*'
   pull_request:
 env:
-  CORE_REPO_SHA: b5c7dea8d2d035b7e820a9aa5414a396cdd6c312
+  CORE_REPO_SHA: 2c1cb20543fcc0bcfe5525d8a695e92babec06db
 
 jobs:
   build:

instrumentation/opentelemetry-instrumentation-system-metrics/src/opentelemetry/instrumentation/system_metrics/__init__.py

@@ -76,11 +76,10 @@
 
 import psutil
 
-from opentelemetry._metrics import get_meter
+from opentelemetry._metrics import Observation, get_meter
 
 # FIXME Remove this pyling disabling line when Github issue is cleared
 # pylint: disable=no-name-in-module
-from opentelemetry._metrics.observation import Observation
 from opentelemetry.instrumentation.instrumentor import BaseInstrumentor
 from opentelemetry.instrumentation.system_metrics.package import _instruments
 from opentelemetry.instrumentation.system_metrics.version import __version__