Add ZeroThreshold field to exponentialHistogramDataPoint in pmetric p…

…ackage (#8769)

**Description:** Add ZeroThreshold field to
exponentialHistogramDataPoint in pmetric package. It's needed to
understand which values fall in the ZeroBucket


Fixes #8802

.chloggen/expose-zerothreshold.yaml

@@ -0,0 +1,18 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: pdata
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add ZeroThreshold field to exponentialHistogramDataPoint in pmetric package.
+
+# One or more tracking issues or pull requests related to the change
+issues: [8802]
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [api]

pdata/internal/cmd/pdatagen/internal/pmetric_package.go

@@ -321,6 +321,12 @@ var exponentialHistogramDataPoint = &messageValueStruct{
 		sumField,
 		minField,
 		maxField,
+		&primitiveField{
+			fieldName:  "ZeroThreshold",
+			returnType: "float64",
+			defaultVal: "float64(0.0)",
+			testVal:    "float64(0.5)",
+		},
 	},
 }