[AI Chat]: Update openai icon to use the dynamically colored version (#36824)

components/ai_chat/resources/common/constants.ts

@@ -19,8 +19,8 @@ const modelIcons = {
   'chat-basic': 'meta-color',
   'chat-glm-4-7-flash': 'zai-color',
   'chat-llama-4-maverick': 'meta-color',
-  'chat-gpt-oss-20b': 'openai-color',
-  'chat-gpt-oss-120b': 'openai-color',
+  'chat-gpt-oss-20b': 'openai',
+  'chat-gpt-oss-120b': 'openai',
   'chat-mistral-large': 'mistral-color',
   'chat-kimi-k2-5': 'kimi-color',
   'chat-qwen-3-235b': 'qwen-color',

ui/webui/resources/BUILD.gn

@@ -361,7 +361,7 @@ leo_icons_sources = [
   "notification.svg",
   "ollama.svg",
   "op-color.svg",
-  "openai-color.svg",
+  "openai.svg",
   "outside.svg",
   "pause-circle.svg",
   "pause-filled.svg",