[SPARK-23122][PYSPARK][FOLLOWUP] Replace registerTempTable by createOrReplaceTempView

## What changes were proposed in this pull request?
Replace `registerTempTable` by `createOrReplaceTempView`.

## How was this patch tested?
N/A

Author: gatorsmile <[email protected]>

Closes apache#20523 from gatorsmile/updateExamples.

Author: gatorsmile

python/pyspark/sql/udf.py

@@ -357,7 +357,7 @@ def registerJavaUDAF(self, name, javaClassName):
 
         >>> spark.udf.registerJavaUDAF("javaUDAF", "test.org.apache.spark.sql.MyDoubleAvg")
         >>> df = spark.createDataFrame([(1, "a"),(2, "b"), (3, "a")],["id", "name"])
-        >>> df.registerTempTable("df")
+        >>> df.createOrReplaceTempView("df")
         >>> spark.sql("SELECT name, javaUDAF(id) as avg from df group by name").collect()
         [Row(name=u'b', avg=102.0), Row(name=u'a', avg=102.0)]
         """

sql/core/src/test/java/test/org/apache/spark/sql/JavaUDAFSuite.java

@@ -46,7 +46,7 @@ public void tearDown() {
   @SuppressWarnings("unchecked")
   @Test
   public void udf1Test() {
-    spark.range(1, 10).toDF("value").registerTempTable("df");
+    spark.range(1, 10).toDF("value").createOrReplaceTempView("df");
     spark.udf().registerJavaUDAF("myDoubleAvg", MyDoubleAvg.class.getName());
     Row result = spark.sql("SELECT myDoubleAvg(value) as my_avg from df").head();
     Assert.assertEquals(105.0, result.getDouble(0), 1.0e-6);