DRILL-7968: ANALYZE TABLE ... REFRESH METADATA fails with FLOAT4 column.

[jnturton]

This commit adds support for java.lang.Float to PojoWriters.java and a
test for the problem described in DRILL-7968 to TestMetastoreCommands.java.

For tables with fewer than ~200 rows and a FLOAT4 column there is no bug: the ANALYZE command succeeds and, indeed, this case is exercised by tests in TestMetastoreCommands.java and alltypes_{required,optional}.parquet which both contain a FLOAT4 column.

But for tables with more than ~200 rows and a FLOAT4 column the ANALYZE command fails with

SQL Error: EXECUTION_ERROR ERROR: PojoRecordReader doesn't yet support conversions from the type [class java.lang.Float].

Failed to setup reader: DynamicPojoRecordReader

E.g. you can reproduce the above with

create table dfs.tmp.test_analyze as
select cast(1 as float) from cp.`employee.json`;

analyze table dfs.tmp.test_analyze refresh metadata;

Documentation

No user-visible change.

Testing

TestMetastoreCommands.java and ad hoc SQL testing.

[luocooong]

@dzamo Nice fix. +1
We can quickly merge this pull request once all the unit tests passed.

[luocooong]

May be shortened to :

@Test // DRILL-7968

[jnturton]

Thank you, I've applied the fixes and a build+test run should kick off presently.

[jnturton]

@luocooong I think all the builds have passed at least once now. There is one cancelled main build reported under Checks. Do I need to do any builds here?

[luocooong]

@dzamo It's time to merge. Squash all the commits for better.