feat: Support Gemini batch inline request's metadata and add test coverage to safety setting

PiperOrigin-RevId: 817811792

Author: yinghsienwu

api-report/genai-node.api.md

@@ -1688,6 +1688,7 @@ export class InlinedEmbedContentResponse {
 export interface InlinedRequest {
     config?: GenerateContentConfig;
     contents?: ContentListUnion;
+    metadata?: Record<string, string>;
     model?: string;
 }
 

api-report/genai-web.api.md

@@ -1688,6 +1688,7 @@ export class InlinedEmbedContentResponse {
 export interface InlinedRequest {
     config?: GenerateContentConfig;
     contents?: ContentListUnion;
+    metadata?: Record<string, string>;
     model?: string;
 }
 

api-report/genai.api.md

@@ -1688,6 +1688,7 @@ export class InlinedEmbedContentResponse {
 export interface InlinedRequest {
     config?: GenerateContentConfig;
     contents?: ContentListUnion;
+    metadata?: Record<string, string>;
     model?: string;
 }
 

src/converters/_batches_converters.ts

@@ -1288,6 +1288,11 @@ export function inlinedRequestToMldev(
     common.setValueByPath(toObject, ['request', 'contents'], transformedList);
   }
 
+  const fromMetadata = common.getValueByPath(fromObject, ['metadata']);
+  if (fromMetadata != null) {
+    common.setValueByPath(toObject, ['metadata'], fromMetadata);
+  }
+
   const fromConfig = common.getValueByPath(fromObject, ['config']);
   if (fromConfig != null) {
     common.setValueByPath(

src/types.ts

@@ -4581,6 +4581,8 @@ export declare interface InlinedRequest {
   /** Content of the request.
    */
   contents?: ContentListUnion;
+  /** The metadata to be associated with the request. */
+  metadata?: Record<string, string>;
   /** Configuration that contains optional model parameters.
    */
   config?: GenerateContentConfig;