feat: add aspect_ratio and image_config for v1beta1 version (#6814)

* feat: add aspect_ratio and image_config for v1beta1 version

PiperOrigin-RevId: 818839226

Source-Link: googleapis/googleapis@db61975

Source-Link: googleapis/googleapis-gen@a5f3c7f
Copy-Tag: eyJwIjoicGFja2FnZXMvZ29vZ2xlLWNsb3VkLWFpcGxhdGZvcm0vLk93bEJvdC55YW1sIiwiaCI6ImE1ZjNjN2YxMjBkYWEzYWMwZjk4ZmJmOTI0NDE5ZDExOTk5MjU1NGEifQ==

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: gcf-owl-bot[bot]

packages/google-cloud-aiplatform/protos/google/cloud/aiplatform/v1beta1/content.proto

@@ -205,6 +205,20 @@ message SpeechConfig {
   VoiceConfig voice_config = 1;
 }
 
+// Config for image generation features.
+message ImageConfig {
+  // Optional. The desired aspect ratio for the generated images. The following
+  // aspect ratios are supported:
+  //
+  // "1:1"
+  // "2:3", "3:2"
+  // "3:4", "4:3"
+  // "4:5", "5:4"
+  // "9:16", "16:9"
+  // "21:9"
+  optional string aspect_ratio = 2 [(google.api.field_behavior) = OPTIONAL];
+}
+
 // Generation config.
 message GenerationConfig {
   // The configuration for routing the request to a specific model.
@@ -429,6 +443,10 @@ message GenerationConfig {
 
   // Optional. Config for model selection.
   ModelConfig model_config = 27 [(google.api.field_behavior) = OPTIONAL];
+
+  // Optional. Config for image generation features.
+  optional ImageConfig image_config = 30
+      [(google.api.field_behavior) = OPTIONAL];
 }
 
 // Safety settings.