feat: Add autoscaling config in the instance to support autoscaling i…

…n systests

PiperOrigin-RevId: 589163292

google/spanner/executor/v1/cloud_executor.proto

@@ -649,6 +649,12 @@ message CreateCloudInstanceAction {
   // Number of processing units (node_count should be set to 0 if used).
   optional int32 processing_units = 6;
 
+  // The autoscaling config for this instance. If non-empty, an autoscaling
+  // instance will be created (processing_units and node_count should be set to
+  // 0 if used).
+  optional google.spanner.admin.instance.v1.AutoscalingConfig
+      autoscaling_config = 7;
+
   // labels.
   map<string, string> labels = 5;
 }
@@ -673,6 +679,12 @@ message UpdateCloudInstanceAction {
   // processing_units or node_count should be present in the message.
   optional int32 processing_units = 5;
 
+  // The autoscaling config for this instance. If non-empty, this instance is
+  // using autoscaling (processing_units and node_count should be set to
+  // 0 if used).
+  optional google.spanner.admin.instance.v1.AutoscalingConfig
+      autoscaling_config = 7;
+
   // labels.
   map<string, string> labels = 6;
 }