feat(logic): add default_predicate_cost parameter

proto/logic/v1beta2/params.proto

@@ -97,19 +97,28 @@ message Interpreter {
 }
 
 // GasPolicy defines the policy for calculating predicate invocation costs and the resulting gas consumption.
+// The gas policy is defined as a list of predicates and their associated unit costs, a default unit cost for predicates
+// if not specified in the list, and a weighting factor that is applied to the unit cost of each predicate to yield.
 message GasPolicy {
   // WeightingFactor is the factor that is applied to the unit cost of each predicate
   // to yield the gas value.
-  // If not provided or set to 0, the default value of 1 is used.
+  // If not provided or set to 0, the value is set to 1.
   string weighting_factor = 1 [
     (gogoproto.moretags) = "yaml:\"weighting_factor\"",
     (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Uint",
     (gogoproto.nullable) = true
   ];
 
+  // DefaultPredicateCost is the default unit cost of a predicate when not specified in the PredicateCosts list.
+  // If not provided or set to 0, the value is set to 1.
+  string default_predicate_cost = 2 [
+    (gogoproto.moretags) = "yaml:\"default_predicate_cost\"",
+    (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Uint",
+    (gogoproto.nullable) = true
+  ];
+
   // PredicateCosts is the list of predicates and their associated unit costs.
-  // If not provided, all predicates have a unit cost of 1 by default.
-  repeated PredicateCost predicate_costs = 2 [
+  repeated PredicateCost predicate_costs = 3 [
     (gogoproto.nullable) = false,
     (gogoproto.moretags) = "yaml:\"predicate_cost\""
   ];