Update unit2/llama-index/tools.ipynb for GmailToolSpec import

Need to add llama-index-tools-google to the PIP install list to enable GmailToolSpec import

unit2/llama-index/tools.ipynb

@@ -22,7 +22,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "!pip install llama-index datasets llama-index-callbacks-arize-phoenix llama-index-vector-stores-chroma llama-index-llms-huggingface-api -U -q"
+    "!pip install llama-index datasets llama-index-callbacks-arize-phoenix llama-index-vector-stores-chroma llama-index-llms-huggingface-api llama-index-tools-google -U -q"
    ]
   },
   {