[telemetry] Sort imports in Telemetry and its dependents.

tools/perf/metrics/cpu.py

Index: tools/perf/metrics/cpu.py
diff --git a/tools/perf/metrics/cpu.py b/tools/perf/metrics/cpu.py
index d0a03040f439246b258fa6ac3cb98c180d49f79b..35c3403fd0df9527b25ff8d1c9b9dadc600a17c0 100644
--- a/tools/perf/metrics/cpu.py
+++ b/tools/perf/metrics/cpu.py
@@ -2,9 +2,10 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-from metrics import Metric
 from telemetry.value import scalar
 
+from metrics import Metric
+
 
 class CpuMetric(Metric):
   """Calulates CPU load over a span of time."""