Fix the issue that multiple histogram are sharing same tags - for historgrams even the resource attributes are the same the bucket tags are always different. For example, if a metric defines histogram buckets ["+Inf", "100"], the expected le tag for these 2 metrics are le:+Inf, le:100 respectively, not le:["+Inf", "100"]
Change the data point value type to float64 so it align with datadog backend data format
["+Inf", "100"], the expectedletag for these 2 metrics arele:+Inf,le:100respectively, notle:["+Inf", "100"]float64so it align with datadog backend data format