Fix AQA notebook image (google#186)

Author: markmcd

site/en/docs/semantic_retriever.ipynb

@@ -48,7 +48,7 @@
       "source": [
         "<table class=\"tfo-notebook-buttons\" align=\"left\">\n",
         "  <td>\n",
-        "    <a target=\"_blank\" href=https://ai.google.dev/docs/semantic_retriever\"><img src=\"https://ai.google.dev/docs/semantic_retriever\" height=\"32\" width=\"32\" />View on Generative AI</a>\n",
+        "    <a target=\"_blank\" href=https://ai.google.dev/docs/semantic_retriever\"><img src=\"https://ai.google.dev/static/site-assets/images/docs/notebook-site-button.png\" height=\"32\" width=\"32\" />View on Generative AI</a>\n",
         "  <td>\n",
         "    <a target=\"_blank\" href=\"https://colab.research.google.com/github/google/generative-ai-docs/blob/main/site/en/docs/semantic_retriever.ipynb\"><img src=\"https://www.tensorflow.org/images/colab_logo_32px.png\" />Run in Google Colab</a>\n",
         "  </td>\n",