[examples] Ensure right side motors are inverted (#3836)

Fixes #3827
Adds MotorController inversion for right side, removes inversion in
setVoltage methods.

Also fixes various XboxController negations (was inconsistent throughout examples).

wpilibcExamples/src/main/cpp/examples/Frisbeebot/cpp/RobotContainer.cpp

@@ -16,8 +16,8 @@ RobotContainer::RobotContainer() {
   // Set up default drive command
   m_drive.SetDefaultCommand(frc2::RunCommand(
       [this] {
-        m_drive.ArcadeDrive(m_driverController.GetLeftY(),
-                            m_driverController.GetRightX());
+        m_drive.ArcadeDrive(-m_driverController.GetLeftY(),
+                            -m_driverController.GetRightX());
       },
       {&m_drive}));
 }