Currently when using `unit` parameter in the `rate` aggregator in time series mode (meaning the `rate` aggregation is defined as a child aggregation of `time_series` aggregation) then this parameter is ignored. We should investigate whether this parameter can be supported for computing rate in time series mode.
x-pack/plugin/analytics/src/main/java/org/elasticsearch/xpack/analytics/rate/InternalResetTrackingRate.java
endValue = rate.endValue;
        }
        return new InternalResetTrackingRate(
            name,
            format,
            metadata,
            startValue,
            endValue,
            toReduce.get(0).startTime,
            toReduce.get(endIndex).endTime,
            resetComp
        );
    }
    @Override
    public XContentBuilder doXContentBody(XContentBuilder builder, Params params) throws IOException {
        return builder.field(CommonFields.VALUE.getPreferredName(), value());
    }
    @Override
    public double value() {
        return (endValue - startValue + resetCompensation) / (endTime - startTime);
    }
    @Override
    public double getValue() {
        return value();
    }
    boolean includes(InternalResetTrackingRate other) {
        return this.startTime < other.startTime && this.endTime > other.endTime;
    }
}