private boolean isNonStringArray(DataType type) {
        return (type instanceof ArrayDataType) && (!type.equals(DataType.getArray(DataType.STRING)));
    }
Fail if:
An SD field explicitly says summary:dynamic , but the field is non-string array, wset, or struct.
If there is an explicitly defined summary class, saying dynamic in one of its summary
fields is always legal.

@author Vegard Havdal
config-model/src/main/java/com/yahoo/schema/processing/SummaryDynamicStructsArrays.java