make up missing ORC write tests on Map of Decimal (NVIDIA#4263)

Signed-off-by: sperlingxx <lovedreamf@gmail.com>

integration_tests/src/main/python/orc_write_test.py

@@ -39,7 +39,9 @@
 orc_write_basic_map_gens = [simple_string_to_string_map_gen] + [MapGen(f(nullable=False), f()) for f in [
     BooleanGen, ByteGen, ShortGen, IntegerGen, LongGen, FloatGen, DoubleGen,
     lambda nullable=True: TimestampGen(start=datetime(1900, 1, 1, tzinfo=timezone.utc), nullable=nullable),
-    lambda nullable=True: DateGen(start=date(1590, 1, 1), nullable=nullable)]]
+    lambda nullable=True: DateGen(start=date(1590, 1, 1), nullable=nullable),
+    lambda nullable=True: DecimalGen(precision=15, scale=1, nullable=nullable),
+    lambda nullable=True: DecimalGen(precision=36, scale=5, nullable=nullable)]]
 
 orc_write_gens_list = [orc_write_basic_gens,
         orc_write_struct_gens_sample,