Revert of [Android][Telemetry] Add support for multiple power monitors

tools/telemetry/telemetry/internal/platform/power_monitor/power_monitor_controller_unittest.py

Index: tools/telemetry/telemetry/internal/platform/power_monitor/power_monitor_controller_unittest.py
diff --git a/tools/telemetry/telemetry/internal/platform/power_monitor/power_monitor_controller_unittest.py b/tools/telemetry/telemetry/internal/platform/power_monitor/power_monitor_controller_unittest.py
index 17140d19964b83d0d3f6ae091f6f7bec642afe33..e4368107f4bbfd08bc159195caeb30ed2834bc7f 100644
--- a/tools/telemetry/telemetry/internal/platform/power_monitor/power_monitor_controller_unittest.py
+++ b/tools/telemetry/telemetry/internal/platform/power_monitor/power_monitor_controller_unittest.py
@@ -25,17 +25,7 @@
 
     class P2(power_monitor.PowerMonitor):
       def __init__(self, value):
-        self._value = {'P2': value}
-      def CanMonitorPower(self):
-        return True
-      def StartMonitoringPower(self, browser):
-        pass
-      def StopMonitoringPower(self):
-        return self._value
-
-    class P3(power_monitor.PowerMonitor):
-      def __init__(self, value):
-        self._value = {'P3': value}
+        self._value = value
       def CanMonitorPower(self):
         return True
       def StartMonitoringPower(self, browser):
@@ -45,12 +35,10 @@
 
     battery = battery_utils.BatteryUtils(None)
     controller = power_monitor_controller.PowerMonitorController(
-        [P1(), P2(1), P3(2)], battery)
+        [P1(), P2(1), P2(2)], battery)
     self.assertEqual(controller.CanMonitorPower(), True)
     controller.StartMonitoringPower(None)
-    controller_returns = controller.StopMonitoringPower()
-    self.assertEqual(controller_returns['P2'], 1)
-    self.assertEqual(controller_returns['P3'], 2)
+    self.assertEqual(controller.StopMonitoringPower(), 1)
 
   @mock.patch.object(battery_utils, 'BatteryUtils')
   def testReenableCharingIfNeeded(self, mock_battery):