Use lowercase SchemaType enum values (#229)

This fixes the serialized values of the `SchemaType` enum to follow [the referenced doc](https://swagger.io/docs/specification/data-models/data-types/) and [the json-schema spec](https://json-schema.org/draft/2020-12/json-schema-core#section-4.2.1) on which the reference is based.

This change makes the JS gemini SDK compatible with the myriad tools like [AJV](https://ajv.js.org/guide/typescript.html) that allow the definition of validators, types, etc using standard json-schema.

In practice the lowercased values appear to work perfectly, but show TypeScript errors.

.changeset/warm-mails-grab.md

@@ -0,0 +1,5 @@
+---
+"@google/generative-ai": minor
+---
+
+Use lowercase SchemaType enum values to match json-schema.

common/api-review/generative-ai-server.api.md

@@ -440,12 +440,12 @@ export interface Schema {
 
 // @public
 export enum SchemaType {
-    ARRAY = "ARRAY",
-    BOOLEAN = "BOOLEAN",
-    INTEGER = "INTEGER",
-    NUMBER = "NUMBER",
-    OBJECT = "OBJECT",
-    STRING = "STRING"
+    ARRAY = "array",
+    BOOLEAN = "boolean",
+    INTEGER = "integer",
+    NUMBER = "number",
+    OBJECT = "object",
+    STRING = "string"
 }
 
 // @public

common/api-review/generative-ai.api.md

@@ -655,12 +655,12 @@ export interface Schema {
 
 // @public
 export enum SchemaType {
-    ARRAY = "ARRAY",
-    BOOLEAN = "BOOLEAN",
-    INTEGER = "INTEGER",
-    NUMBER = "NUMBER",
-    OBJECT = "OBJECT",
-    STRING = "STRING"
+    ARRAY = "array",
+    BOOLEAN = "boolean",
+    INTEGER = "integer",
+    NUMBER = "number",
+    OBJECT = "object",
+    STRING = "string"
 }
 
 // @public

docs/reference/main/generative-ai.schematype.md

@@ -16,10 +16,10 @@ export declare enum SchemaType
 
 |  Member | Value | Description |
 |  --- | --- | --- |
-|  ARRAY | <code>&quot;ARRAY&quot;</code> | Array type. |
-|  BOOLEAN | <code>&quot;BOOLEAN&quot;</code> | Boolean type. |
-|  INTEGER | <code>&quot;INTEGER&quot;</code> | Integer type. |
-|  NUMBER | <code>&quot;NUMBER&quot;</code> | Number type. |
-|  OBJECT | <code>&quot;OBJECT&quot;</code> | Object type. |
-|  STRING | <code>&quot;STRING&quot;</code> | String type. |
+|  ARRAY | <code>&quot;array&quot;</code> | Array type. |
+|  BOOLEAN | <code>&quot;boolean&quot;</code> | Boolean type. |
+|  INTEGER | <code>&quot;integer&quot;</code> | Integer type. |
+|  NUMBER | <code>&quot;number&quot;</code> | Number type. |
+|  OBJECT | <code>&quot;object&quot;</code> | Object type. |
+|  STRING | <code>&quot;string&quot;</code> | String type. |
 

docs/reference/server/generative-ai.schematype.md

@@ -16,10 +16,10 @@ export declare enum SchemaType
 
 |  Member | Value | Description |
 |  --- | --- | --- |
-|  ARRAY | <code>&quot;ARRAY&quot;</code> | Array type. |
-|  BOOLEAN | <code>&quot;BOOLEAN&quot;</code> | Boolean type. |
-|  INTEGER | <code>&quot;INTEGER&quot;</code> | Integer type. |
-|  NUMBER | <code>&quot;NUMBER&quot;</code> | Number type. |
-|  OBJECT | <code>&quot;OBJECT&quot;</code> | Object type. |
-|  STRING | <code>&quot;STRING&quot;</code> | String type. |
+|  ARRAY | <code>&quot;array&quot;</code> | Array type. |
+|  BOOLEAN | <code>&quot;boolean&quot;</code> | Boolean type. |
+|  INTEGER | <code>&quot;integer&quot;</code> | Integer type. |
+|  NUMBER | <code>&quot;number&quot;</code> | Number type. |
+|  OBJECT | <code>&quot;object&quot;</code> | Object type. |
+|  STRING | <code>&quot;string&quot;</code> | String type. |
 

types/function-calling.ts

@@ -86,17 +86,17 @@ export declare interface FunctionDeclarationsTool {
  */
 export enum SchemaType {
   /** String type. */
-  STRING = "STRING",
+  STRING = "string",
   /** Number type. */
-  NUMBER = "NUMBER",
+  NUMBER = "number",
   /** Integer type. */
-  INTEGER = "INTEGER",
+  INTEGER = "integer",
   /** Boolean type. */
-  BOOLEAN = "BOOLEAN",
+  BOOLEAN = "boolean",
   /** Array type. */
-  ARRAY = "ARRAY",
+  ARRAY = "array",
   /** Object type. */
-  OBJECT = "OBJECT",
+  OBJECT = "object",
 }
 
 /**