[SPARK-33607][SS][WEBUI] Input Rate timeline/histogram aren't rendered if built with Scala 2.13

### What changes were proposed in this pull request?

This PR fixes an issue that the histogram and timeline aren't rendered in the `Streaming Query Statistics` page if we built Spark with Scala 2.13.

![before-fix-the-issue](https://user-images.githubusercontent.com/4736016/100612855-f543d700-3356-11eb-90d9-ede57b8b3f4f.png)
![NaN_Error](https://user-images.githubusercontent.com/4736016/100612879-00970280-3357-11eb-97cf-43978bbe2d3a.png)

The reason is [`maxRecordRate` can be `NaN`](https://github.com/apache/spark/blob/master/sql/core/src/main/scala/org/apache/spark/sql/streaming/ui/StreamingQueryStatisticsPage.scala#L371) for Scala 2.13.

The `NaN` is the result of [`query.recentProgress.map(_.inputRowsPerSecond).max`](https://github.com/apache/spark/blob/master/sql/core/src/main/scala/org/apache/spark/sql/streaming/ui/StreamingQueryStatisticsPage.scala#L372) when the first element of `query.recentProgress.map(_.inputRowsPerSecond)` is `NaN`.
Actually, the comparison logic for `Double` type was changed in Scala 2.13.
scala/bug#12107
scala/scala#6410

So this issue happens as of Scala 2.13.

The root cause of the `NaN` is [here](https://github.com/apache/spark/blob/master/sql/core/src/main/scala/org/apache/spark/sql/execution/streaming/ProgressReporter.scala#L164).
This `NaN` seems to be an initial value of `inputTimeSec` so I think `Double.PositiveInfinity` is suitable rather than `NaN` and this change can resolve this issue.

### Why are the changes needed?

To make sure we can use the histogram/timeline with Scala 2.13.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

First, I built with the following commands.
```
$ /dev/change-scala-version.sh 2.13
$ build/sbt -Phive -Phive-thriftserver -Pscala-2.13 package
```

Then, ran the following query (this is brought from #30427 ).
```
import org.apache.spark.sql.streaming.Trigger
val query = spark
  .readStream
  .format("rate")
  .option("rowsPerSecond", 1000)
  .option("rampUpTime", "10s")
  .load()
  .selectExpr("*", "CAST(CAST(timestamp AS BIGINT) - CAST((RAND() * 100000) AS BIGINT) AS TIMESTAMP) AS tsMod")
  .selectExpr("tsMod", "mod(value, 100) as mod", "value")
  .withWatermark("tsMod", "10 seconds")
  .groupBy(window($"tsMod", "1 minute", "10 seconds"), $"mod")
  .agg(max("value").as("max_value"), min("value").as("min_value"), avg("value").as("avg_value"))
  .writeStream
  .format("console")
  .trigger(Trigger.ProcessingTime("5 seconds"))
  .outputMode("append")
  .start()
```

Finally, I confirmed that the timeline and histogram are rendered.
![after-fix-the-issue](https://user-images.githubusercontent.com/4736016/100612736-c9285600-3356-11eb-856d-7e53cc656c36.png)

```

Closes #30546 from sarutak/ss-nan.

Authored-by: Kousuke Saruta <[email protected]>
Signed-off-by: Jungtaek Lim (HeartSaVioR) <[email protected]>

Author: sarutak

sql/core/src/main/scala/org/apache/spark/sql/execution/streaming/ProgressReporter.scala

@@ -161,7 +161,7 @@ trait ProgressReporter extends Logging {
     val inputTimeSec = if (lastTriggerStartTimestamp >= 0) {
       (currentTriggerStartTimestamp - lastTriggerStartTimestamp).toDouble / MILLIS_PER_SECOND
     } else {
-      Double.NaN
+      Double.PositiveInfinity
     }
     logDebug(s"Execution stats: $executionStats")