Use `AccessibleObject#canAccess` instead of `AccessibleObject#isAccessible`

[warn] /Users/yangjie01/SourceCode/git/spark-mine-sbt/core/src/test/scala/org/apache/spark/util/UtilsSuite.scala:258:15: method isAccessible in class AccessibleObject is deprecated (since 9)
[warn] Applicable -Wconf / @nowarn filters for this warning: msg=<part of the message>, cat=deprecation, site=org.apache.spark.util.UtilsSuite.getFieldValue, origin=java.lang.reflect.AccessibleObject.isAccessible, version=9
[warn]     if (field.isAccessible()) {
[warn]