[SPARK-47739][SQL] Register logical avro type

### What changes were proposed in this pull request?
In this pull request I propose that we register logical avro types when we initialize `AvroUtils` and `AvroFileFormat`, otherwise for first schema discovery we might get wrong result on very first execution after spark starts.
<img width="1727" alt="image" src="https://github.com/apache/spark/assets/150366084/3eaba6e3-34ec-4ca9-ae89-d0259ce942ba">

example
```scala
val new_schema = """
     | {
     |   "type": "record",
     |   "name": "Entry",
     |   "fields": [
     |     {
     |       "name": "rate",
     |       "type": [
     |         "null",
     |         {
     |           "type": "long",
     |           "logicalType": "custom-decimal",
     |           "precision": 38,
     |           "scale": 9
     |         }
     |       ],
     |       "default": null
     |     }
     |   ]
     | }""".stripMargin
spark.read.format("avro").option("avroSchema", new_schema).load().printSchema // maps to long - WRONG
spark.read.format("avro").option("avroSchema", new_schema).load().printSchema // maps to Decimal - CORRECT
```

### Why are the changes needed?
To fix issue with resolving avro schema upon spark startup.

### Does this PR introduce _any_ user-facing change?
No, its a bugfix

### How was this patch tested?
Unit tests

### Was this patch authored or co-authored using generative AI tooling?
No

Closes apache#45895 from milastdbx/dev/milast/fixAvroLogicalTypeRegistration.

Lead-authored-by: milastdbx <[email protected]>
Co-authored-by: Dongjoon Hyun <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>

connector/avro/src/main/scala/org/apache/spark/sql/avro/AvroFileFormat.scala

@@ -43,6 +43,8 @@ import org.apache.spark.util.SerializableConfiguration
 private[sql] class AvroFileFormat extends FileFormat
   with DataSourceRegister with Logging with Serializable {
 
+  AvroFileFormat.registerCustomAvroTypes()
+
   override def equals(other: Any): Boolean = other match {
     case _: AvroFileFormat => true
     case _ => false
@@ -173,10 +175,17 @@ private[sql] class AvroFileFormat extends FileFormat
 private[avro] object AvroFileFormat {
   val IgnoreFilesWithoutExtensionProperty = "avro.mapred.ignore.inputs.without.extension"
 
-  // Register the customized decimal type backed by long.
-  LogicalTypes.register(CustomDecimal.TYPE_NAME, new LogicalTypes.LogicalTypeFactory {
-    override def fromSchema(schema: Schema): LogicalType = {
-      new CustomDecimal(schema)
-    }
-  })
+  /**
+   * Register Spark defined custom Avro types.
+   */
+  def registerCustomAvroTypes(): Unit = {
+    // Register the customized decimal type backed by long.
+    LogicalTypes.register(CustomDecimal.TYPE_NAME, new LogicalTypes.LogicalTypeFactory {
+      override def fromSchema(schema: Schema): LogicalType = {
+        new CustomDecimal(schema)
+      }
+    })
+  }
+
+  registerCustomAvroTypes()
 }

connector/avro/src/test/scala/org/apache/spark/sql/avro/AvroLogicalTypeInitSuite.scala

@@ -0,0 +1,76 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.spark.sql.avro
+
+import org.apache.spark.SparkConf
+import org.apache.spark.sql.QueryTest
+import org.apache.spark.sql.internal.SQLConf
+import org.apache.spark.sql.test.SharedSparkSession
+import org.apache.spark.sql.types.DecimalType
+
+/**
+ * Test suite for Avro logical type initialization.
+ * Tests here must run in isolation, otherwise some other test might
+ * initialize variable and make this test flaky
+ */
+abstract class AvroLogicalTypeInitSuite
+  extends QueryTest
+  with SharedSparkSession {
+
+  test("SPARK-47739: custom logical type registration test") {
+    val avroTypeJson =
+      """
+         |{
+         |  "type": "record",
+         |  "name": "Entry",
+         |  "fields": [
+         |    {
+         |      "name": "test_col",
+         |      "type": [
+         |        "null",
+         |        {
+         |          "type": "long",
+         |          "logicalType": "custom-decimal",
+         |          "precision": 38,
+         |          "scale": 9
+         |        }
+         |      ],
+         |      "default": null
+         |    }
+         |  ]
+         |}
+         |
+   """.stripMargin
+
+    val df = spark.read.format("avro").option("avroSchema", avroTypeJson).load()
+    assert(df.schema.fields(0).dataType == DecimalType(38, 9))
+  }
+}
+
+class AvroV1LogicalTypeInitSuite extends AvroLogicalTypeInitSuite {
+  override protected def sparkConf: SparkConf =
+    super
+      .sparkConf
+      .set(SQLConf.USE_V1_SOURCE_LIST, "avro")
+}
+
+class AvroV2LogicalTypeInitSuite extends AvroLogicalTypeInitSuite {
+  override protected def sparkConf: SparkConf =
+    super
+      .sparkConf
+      .set(SQLConf.USE_V1_SOURCE_LIST, "")
+}