[wpimath] Add Rotation2d.fromRadians factory (#4178)

wpimath/src/main/java/edu/wpi/first/math/geometry/Rotation2d.java

@@ -58,6 +58,16 @@ public class Rotation2d implements Interpolatable<Rotation2d> {
     m_value = Math.atan2(m_sin, m_cos);
   }
 
+  /**
+   * Constructs and returns a Rotation2d with the given radian value.
+   *
+   * @param radians The value of the angle in degrees.
+   * @return The rotation object with the desired angle value.
+   */
+  public static Rotation2d fromRadians(double radians) {
+    return new Rotation2d(radians);
+  }
+
   /**
    * Constructs and returns a Rotation2d with the given degree value.
    *