[FEA] Support Y in from_unixtime

[viadea]

I wish we can support below fallback:

!Expression <FromUnixTime> from_unixtime(cast((cast(xxx as double) / 100.0) as bigint), Y-MM-dd, Some(Etc/UTC)) cannot run on GPU because Failed to convert Unsupported character: Y null

[viadea]

Gen-AI can generate the code to repro above fallback message now:)

# Create a sample DataFrame with a timestamp column
data = [(1633072800000.0,)]
df = spark.createDataFrame(data, ["timestamp_ms"])
df.createOrReplaceTempView("sample_data")

spark.conf.set("spark.sql.legacy.timeParserPolicy","LEGACY")
# Perform the from_unixtime operation that causes the fallback
result = spark.sql("""
    SELECT 
        from_unixtime(
            CAST((CAST(timestamp_ms AS DOUBLE) / 100.0) AS BIGINT), 
            'Y-MM-dd'
        ) AS formatted_time 
    FROM sample_data
""")

# Show the result
result.show()

+--------------+
|formatted_time|
+--------------+
|    2487-07-02|
+--------------+