Move some DrivetrainConfig types to flatbuffers

This makes it so that we can start to implement the DrivetrainConfig as
a flatbuffer.

Change-Id: I69b92fcc436e82662d01a329d048a80c67267267
Signed-off-by: James Kuszmaul <jabukuszmaul+collab@gmail.com>
diff --git a/y2024/control_loops/drivetrain/drivetrain_base.cc b/y2024/control_loops/drivetrain/drivetrain_base.cc
index 325dae8..ebb61ac 100644
--- a/y2024/control_loops/drivetrain/drivetrain_base.cc
+++ b/y2024/control_loops/drivetrain/drivetrain_base.cc
@@ -9,7 +9,7 @@
 #include "y2024/control_loops/drivetrain/kalman_drivetrain_motor_plant.h"
 #include "y2024/control_loops/drivetrain/polydrivetrain_dog_motor_plant.h"
 
-using ::frc971::control_loops::drivetrain::DownEstimatorConfig;
+using ::frc971::control_loops::drivetrain::DownEstimatorConfigT;
 using ::frc971::control_loops::drivetrain::DrivetrainConfig;
 using ::frc971::control_loops::drivetrain::LineFollowConfig;
 
@@ -25,10 +25,10 @@
   // Yaw of the IMU relative to the robot frame.
   static constexpr double kImuYaw = 0.0;
   static DrivetrainConfig<double> kDrivetrainConfig{
-      ::frc971::control_loops::drivetrain::ShifterType::SIMPLE_SHIFTER,
-      ::frc971::control_loops::drivetrain::LoopType::CLOSED_LOOP,
-      ::frc971::control_loops::drivetrain::GyroType::SPARTAN_GYRO,
-      ::frc971::control_loops::drivetrain::IMUType::IMU_FLIPPED_X,
+      ::frc971::control_loops::drivetrain::ShifterType::kSimpleShifter,
+      ::frc971::control_loops::drivetrain::LoopType::kClosedLoop,
+      ::frc971::control_loops::drivetrain::GyroType::kSpartanGyro,
+      ::frc971::control_loops::drivetrain::ImuType::kImuFlippedX,
 
       drivetrain::MakeDrivetrainLoop,
       drivetrain::MakeVelocityDrivetrainLoop,
@@ -59,8 +59,7 @@
        0.0, std::sin(kImuYaw), std::cos(kImuYaw), 0.0, 0.0, 0.0, 1.0)
           .finished(),
       false /*is_simulated*/,
-      DownEstimatorConfig{.gravity_threshold = 0.015,
-                          .do_accel_corrections = 1000},
+      DownEstimatorConfigT{{}, 0.015, 1000},
       LineFollowConfig{
           .Q = Eigen::Matrix3d((::Eigen::DiagonalMatrix<double, 3>().diagonal()
                                     << 1.0 / ::std::pow(0.1, 2),