[SPARK-3365][SQL]Wrong schema generated for List type

[tianyi]

This PR fix the issue SPARK-3365.
The reason is Spark generated wrong schema for the type List in ScalaReflection.scala
for example:

the generated schema for type Seq[String] is:

{"name":"x","type":{"type":"array","elementType":"string","containsNull":true},"nullable":true,"metadata":{}}`

the generated schema for type List[String] is:

{"name":"x","type":{"type":"struct","fields":[]},"nullable":true,"metadata":{}}`

[AmplabJenkins]

Can one of the admins verify this patch?

[liancheng]

ok to test

[liancheng]

This LGTM, let's wait for Jenkins. Thanks for working on this!

[liancheng]

add to whitelist

[SparkQA]

Test build #27411 has started for PR 4581 at commit a8bd6fe.

• This patch merges cleanly.

[liancheng]

@tianyi After rethinking about this, now I tend to the solution you proposed originally on JIRA, namely move the Product clause below Seq. Usually types like List[T] which extend Seq[T] with Product should be viewed as a Seq at the first place.

[SparkQA]

Test build #27412 has started for PR 4581 at commit a097e86.

• This patch merges cleanly.

[SparkQA]

Test build #27411 has finished for PR 4581 at commit a8bd6fe.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[AmplabJenkins]

Test PASSed.
Refer to this link for build results (access rights to CI server needed):
https://amplab.cs.berkeley.edu/jenkins//job/SparkPullRequestBuilder/27411/
Test PASSed.

[SparkQA]

Test build #27412 has finished for PR 4581 at commit a097e86.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[AmplabJenkins]

Test PASSed.
Refer to this link for build results (access rights to CI server needed):
https://amplab.cs.berkeley.edu/jenkins//job/SparkPullRequestBuilder/27412/
Test PASSed.

[liancheng]

Thanks! Merging to master and branch-1.3.