Feature Request: support SubstringComparator with NOT_EQUAL

[gsbingo17]

We are refactoring the application with Cloud Bigtable from HBase.

The code snippet using HBase:

if (StringUtils.isNotBlank(value)) {
                    SubstringComparator notContainsValue = new SubstringComparator(value);
                    SingleColumnValueFilter filter = new SingleColumnValueFilter(CF, Bytes.toBytes(CQ1),
                            CompareFilter.CompareOp.NOT_EQUAL, notContainsValue);
                    filterList.addFilter(filter);
                }

However, Bigtable's HBase API does not support SubstringComparator with NOT_EQUAL. And we got the following error:

reason='ValueFilter must have either a BinaryComparator with any compareOp or a RegexStringComparator with an EQUAL compareOp. Found (SubstringComparator, NOT_EQUAL)'}