[BattOr] Do not catch exception when failing to start battor.

telemetry/telemetry/internal/platform/tracing_agent/battor_tracing_agent.py

Index: telemetry/telemetry/internal/platform/tracing_agent/battor_tracing_agent.py
diff --git a/telemetry/telemetry/internal/platform/tracing_agent/battor_tracing_agent.py b/telemetry/telemetry/internal/platform/tracing_agent/battor_tracing_agent.py
index 483940bf8b30b80c9982f80e66a428d51c60706d..7c859dbee363417c8b13323f0c62cdac6c0bb8ca 100644
--- a/telemetry/telemetry/internal/platform/tracing_agent/battor_tracing_agent.py
+++ b/telemetry/telemetry/internal/platform/tracing_agent/battor_tracing_agent.py
@@ -73,14 +73,15 @@ class BattOrTracingAgent(tracing_agent.TracingAgent):
     except battor_error.BattorError:
       if self._battery:
         self._battery.SetCharging(True)
-      logging.exception('Failure in starting tracing on BattOr.')
-      return False
+      raise
 
   def StopAgentTracing(self):
     """Stops tracing on the BattOr."""
-    self._battor.StopTracing()
-    if self._battery:
-      self._battery.SetCharging(True)
+    try:
+      self._battor.StopTracing()
+    finally:
+      if self._battery:
+        self._battery.SetCharging(True)
 
   def SupportsExplicitClockSync(self):
     return self._battor.SupportsExplicitClockSync()