fix(iceberg): fix decimal type for iceberg source (#17854) (#17859)

Co-authored-by: Dylan <[email protected]>

src/common/src/array/arrow/arrow_impl.rs

@@ -519,6 +519,7 @@ pub trait FromArrow {
             Int16 => self.from_int16_array(array.as_any().downcast_ref().unwrap()),
             Int32 => self.from_int32_array(array.as_any().downcast_ref().unwrap()),
             Int64 => self.from_int64_array(array.as_any().downcast_ref().unwrap()),
+            Decimal128(_, _) => self.from_decimal128_array(array.as_any().downcast_ref().unwrap()),
             Decimal256(_, _) => self.from_int256_array(array.as_any().downcast_ref().unwrap()),
             Float32 => self.from_float32_array(array.as_any().downcast_ref().unwrap()),
             Float64 => self.from_float64_array(array.as_any().downcast_ref().unwrap()),
@@ -596,6 +597,13 @@ pub trait FromArrow {
         Ok(ArrayImpl::Int256(array.into()))
     }
 
+    fn from_decimal128_array(
+        &self,
+        array: &arrow_array::Decimal128Array,
+    ) -> Result<ArrayImpl, ArrayError> {
+        Ok(ArrayImpl::Decimal(array.try_into()?))
+    }
+
     fn from_float32_array(
         &self,
         array: &arrow_array::Float32Array,