Tune y2020/2021 drivetrain controller

The falcons are proving to be way more aggressive than CIMs were.  The
higher kt means that the controllers are more aggressive by default.
Detune both the voltage error and the controller enough to make it
stable and smooth.

Change-Id: I7c32ad7f8f2e9ca9d1312ddb176cbf45524eaf8a
diff --git a/y2020/control_loops/drivetrain/localizer_test.cc b/y2020/control_loops/drivetrain/localizer_test.cc
index 3798c34..d440aaf 100644
--- a/y2020/control_loops/drivetrain/localizer_test.cc
+++ b/y2020/control_loops/drivetrain/localizer_test.cc
@@ -436,7 +436,7 @@
   VerifyNearGoal();
   // Due to accelerometer drift, the straight-line driving tends to be less
   // accurate...
-  EXPECT_TRUE(VerifyEstimatorAccurate(0.1));
+  EXPECT_TRUE(VerifyEstimatorAccurate(0.15));
 }
 
 // Tests that camera updates with a perfect models results in no errors.
@@ -537,7 +537,7 @@
   // If we remove the disturbance, we should now be correct.
   drivetrain_plant_.mutable_state()->topRows(3) -= disturbance;
   VerifyNearGoal(5e-3);
-  EXPECT_TRUE(VerifyEstimatorAccurate(1e-3));
+  EXPECT_TRUE(VerifyEstimatorAccurate(2e-3));
 }
 
 // Tests that we don't reject camera measurements when the turret is spinning