Compilation error occurs for rules written in mvel dialect in executable model.

Issue

Compiling rules written in mvel dialect which use binary operation taking java.math.BigDecimal type operands causes an error.
When I build a maven project which contains the following rule in executable model,

package org.example.reproducer

import org.example.reproducer.Person;

dialect "mvel"

rule "salary-increase"
    when
        $p : Person( age >= 26 )
    then
        System.out.println("***** Action of rule \"salary-increase\"");
        $p.salary = $p.salary + 50000;
end

compilation error occurs with the messages like below.

[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] /path/to/project1/target/generated-sources/drools-model-compiler/main/java/org/example/reproducer/Rules2a5935db629e45d8b951392188ce055cRuleMethods0.java:[36,76] salary has private access in org.example.reproducer.Person
[ERROR] /path/to/project1/target/generated-sources/drools-model-compiler/main/java/org/example/reproducer/Rules2a5935db629e45d8b951392188ce055cRuleMethods0.java:[36,101] bad operand types for binary operator '+'
  first type:  java.math.BigDecimal
  second type: int
[INFO] 2 errors

Where $p.salary is a java.math.BigDecimal type property of Person.