[build] Change defaults for Java lints (#4300)

Removes the need to individually suppress the "serial" warning.

wpimath/src/main/java/edu/wpi/first/math/spline/SplineParameterizer.java

@@ -57,7 +57,6 @@ public final class SplineParameterizer {
     }
   }
 
-  @SuppressWarnings("serial")
   public static class MalformedSplineException extends RuntimeException {
     /**
      * Create a new exception with the given message.