Make TestECPolicyDisabler work with Hadoop 3

TestECPolicyDisabler is not compatible with hadoop 3. The following error messages are produced by command `mvn clean install -DskipTests -Dhadoop.version=3.1.0 -Dhadoop.majorversion=3 -Phadoop-3`

[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] /home/chia7712/oozie/tools/src/test/java/org/apache/oozie/tools/TestECPolicyDisabler.java:[50,71] getErasureCodingPolicy(org.apache.hadoop.fs.Path) in org.apache.oozie.tools.TestECPolicyDisabler.MockDistributedFileSystem cannot override getErasureCodingPolicy(org.apache.hadoop.fs.Path) in org.apache.hadoop.hdfs.DistributedFileSystem
return type org.apache.hadoop.hdfs.protocol.SystemErasureCodingPolicies.ReplicationPolicy is not compatible with org.apache.hadoop.hdfs.protocol.ErasureCodingPolicy

The root cause is the method `getErasureCodingPolicy` was introduced in hadoop 3 and the method signature is different to mock fs of TestECPolicyDisabler. Fortunately, all we want to test is the static method 'ECPolicyDisabler#check' so we can add a new argument to make it be able to check another method.