IsMonotonic is inconsistent for opencensus bridge between go and java

[ktong]

The opencensus shim in Java set IsMonotonic to true, https://github.com/open-telemetry/opentelemetry-java/blob/main/opencensus-shim/src/main/java/io/opentelemetry/opencensusshim/internal/metrics/MetricAdapter.java#L158

But Opencensus bridge in Go set IsMonotonic to false

opentelemetry-go/bridge/opencensus/internal/ocmetric/metric.go

Line 95 in ccbc38e

return metricdata.Sum[N]{DataPoints: points, Temporality: metricdata.CumulativeTemporality}, err

, which cause counter metric shows incorrect.