Update metric.graphqls

Support #4288

metric.graphqls

@@ -74,5 +74,6 @@ extend type Query {
     # Such as, should us this to query the result of func percentile(50,75,90,95,99) in OAL,
     # then five lines will be responsed, p50 is the first element of return value.
     getMultipleLinearIntValues(metric: MetricCondition!, numOfLinear: Int!, duration: Duration!): [IntValues!]!
+    getSubsetOfMultipleLinearIntValues(metric: MetricCondition!, linearIndex: [Int!]!, duration: Duration!): [IntValues!]!
     getThermodynamic(metric: MetricCondition!, duration: Duration!): Thermodynamic
 }