[SPARK-22583] First delegation token renewal time is not 75% of renewal time in Mesos

The first scheduled renewal time is is set to the exact expiration time,
and all subsequent renewal times are 75% of the renewal time. This makes
it so that the inital renewal time is also 75%.

## What changes were proposed in this pull request?

Set the initial renewal time to be 75% of renewal time.

## How was this patch tested?

Tested locally in a test HDFS cluster, checking various renewal times.

Author: Kalvin Chau <[email protected]>

Closes #19798 from kalvinnchau/fix-inital-renewal-time.

Author: Kalvin Chau

resource-managers/mesos/src/main/scala/org/apache/spark/scheduler/cluster/mesos/MesosHadoopDelegationTokenManager.scala

@@ -63,7 +63,7 @@ private[spark] class MesosHadoopDelegationTokenManager(
       val hadoopConf = SparkHadoopUtil.get.newConfiguration(conf)
       val rt = tokenManager.obtainDelegationTokens(hadoopConf, creds)
       logInfo(s"Initialized tokens: ${SparkHadoopUtil.get.dumpTokens(creds)}")
-      (SparkHadoopUtil.get.serialize(creds), rt)
+      (SparkHadoopUtil.get.serialize(creds), SparkHadoopUtil.getDateOfNextUpdate(rt, 0.75))
     } catch {
       case e: Exception =>
         logError(s"Failed to fetch Hadoop delegation tokens $e")