[SPARK-26094][CORE][STREAMING] createNonEcFile creates parent dirs.

## What changes were proposed in this pull request?

We explicitly avoid files with hdfs erasure coding for the streaming WAL
and for event logs, as hdfs EC does not support all relevant apis.
However, the new builder api used has different semantics -- it does not
create parent dirs, and it does not resolve relative paths.  This
updates createNonEcFile to have similar semantics to the old api.

## How was this patch tested?

Ran tests with the WAL pointed at a non-existent dir, which failed before this change.  Manually tested the new function with a relative path as well.
Unit tests via jenkins.

Closes apache#23092 from squito/SPARK-26094.

Authored-by: Imran Rashid <irashid@cloudera.com>
Signed-off-by: Marcelo Vanzin <vanzin@cloudera.com>

core/src/main/scala/org/apache/spark/deploy/SparkHadoopUtil.scala

@@ -466,7 +466,13 @@ private[spark] object SparkHadoopUtil {
     try {
       // Use reflection as this uses apis only avialable in hadoop 3
       val builderMethod = fs.getClass().getMethod("createFile", classOf[Path])
-      val builder = builderMethod.invoke(fs, path)
+      // the builder api does not resolve relative paths, nor does it create parent dirs, while
+      // the old api does.
+      if (!fs.mkdirs(path.getParent())) {
+        throw new IOException(s"Failed to create parents of $path")
+      }
+      val qualifiedPath = fs.makeQualified(path)
+      val builder = builderMethod.invoke(fs, qualifiedPath)
       val builderCls = builder.getClass()
       // this may throw a NoSuchMethodException if the path is not on hdfs
       val replicateMethod = builderCls.getMethod("replicate")