[Telemetry] Reduce misleading spam in unittest output.

tools/telemetry/telemetry/core/exceptions.py

Index: tools/telemetry/telemetry/core/exceptions.py
diff --git a/tools/telemetry/telemetry/core/exceptions.py b/tools/telemetry/telemetry/core/exceptions.py
index 7837adb0abefd55450897fb15db43bbe831e5852..83ac24be60c4b0ff6f0f6fbdb144a168b6d33dbf 100644
--- a/tools/telemetry/telemetry/core/exceptions.py
+++ b/tools/telemetry/telemetry/core/exceptions.py
@@ -44,6 +44,10 @@ class ProcessGoneException(Exception):
   """Represents a process that no longer exists for an unknown reason."""
 
 
+class IntentionalException(Exception):
+  """Represent an exception raised by a unittest which is not printed."""
+
+
 class LoginException(Exception):
   pass