[wpilibj] Fix ADIS16448 getRate to return rate instead of angle (#3974)

wpilibj/src/main/java/edu/wpi/first/wpilibj/ADIS16448_IMU.java

@@ -961,11 +961,11 @@ public class ADIS16448_IMU implements AutoCloseable, NTSendable {
   public synchronized double getRate() {
     switch (m_yaw_axis) {
       case kX:
-        return getGyroAngleX();
+        return getGyroRateX();
       case kY:
-        return getGyroAngleY();
+        return getGyroRateY();
       case kZ:
-        return getGyroAngleZ();
+        return getGyroRateZ();
       default:
         return 0.0;
     }