Metrics: unify codahale metric frequency unit between metastore and hiveserver2

Currently, different default value and even different unit are used for json metric file generation frequency (for metastore and hiveserver2), which is confusing, especially in a situation when a metastore config can fall back to a corresponding hive config (metastore.metrics.file.frequency -> hive.service.metrics.file.frequency).
I think ms would be appropriate for both of them, without even changing the default 1minute for metastore (so changing it to 60000ms is my proposal)

hive.service.metrics.file.frequency

Hiveserver2:
https://github.com/apache/hive/blob/master/common/src/java/org/apache/hadoop/hive/conf/HiveConf.java

    HIVE_METRICS_JSON_FILE_INTERVAL("hive.service.metrics.file.frequency", "5000ms",
        new TimeValidator(TimeUnit.MILLISECONDS),
        "For metric class org.apache.hadoop.hive.common.metrics.metrics2.JsonFileMetricsReporter, " +
        "the frequency of updating JSON metrics file."),

Metastore:
https://github.com/apache/hive/blob/master/standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/conf/MetastoreConf.java

    METRICS_JSON_FILE_INTERVAL("metastore.metrics.file.frequency",
        "hive.service.metrics.file.frequency", 1, TimeUnit.MINUTES,
        "For json metric reporter, the frequency of updating JSON metrics file."),