[BUG] convertDecimal64ToDecimal32Wrapper leaks ColumnView instances

[jlowe]

com.nvidia.spark.rapids.ParquetPartitionReaderBase#convertDecimal64ToDecimal32Wrapper instantiates ColumnView instances without closing them. For example, child and newChild are both ColumnView instances and neither are closed.

      } else if (dt == DType.LIST) {
        val child = cv.getChildColumnView(0)
        val newChild = convertDecimal64ToDecimal32(child, precision, newCols)
        if (child == newChild) {
          cv
        } else {
          cv.replaceListChild(newChild)
        }
      } else if (dt == DType.STRUCT) {

Each ColumnView corresponds to a native structure that needs to be closed to release the native memory.