[SPARK-20465][CORE] Throws a proper exception when any temp directory could not be got

## What changes were proposed in this pull request?

This PR proposes to throw an exception with better message rather than `ArrayIndexOutOfBoundsException` when temp directories could not be created.

Running the commands below:

```bash
./bin/spark-shell --conf spark.local.dir=/NONEXISTENT_DIR_ONE,/NONEXISTENT_DIR_TWO
```

produces ...

**Before**

```
Exception in thread "main" java.lang.ExceptionInInitializerError
        ...
Caused by: java.lang.ArrayIndexOutOfBoundsException: 0
        ...
```

**After**

```
Exception in thread "main" java.lang.ExceptionInInitializerError
        ...
Caused by: java.io.IOException: Failed to get a temp directory under [/NONEXISTENT_DIR_ONE,/NONEXISTENT_DIR_TWO].
        ...
```

## How was this patch tested?

Unit tests in `LocalDirsSuite.scala`.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #17768 from HyukjinKwon/throws-temp-dir-exception.