Adds support for gemma_270m to checkpoint converter (#2380)

* Adds support for gemma_270m to checkpoint converter

* format

* removes assertion

* format

* removes launch.json

Author: JyotinderSingh

tools/checkpoint_conversion/convert_gemma3_checkpoints.py

@@ -10,8 +10,8 @@
 Usage:
 ```shell
 cd tools/checkpoint_conversion
-python convert_gemma_checkpoints.py --preset gemma3_instruct_1b
-python convert_gemma_checkpoints.py --preset gemma3_instruct_4b
+python convert_gemma3_checkpoints.py --preset gemma3_instruct_1b
+python convert_gemma3_checkpoints.py --preset gemma3_instruct_4b
 ```
 """
 
@@ -43,6 +43,15 @@
 
 PRESET_MAP = {
     # === Text ===
+    # 270M
+    "gemma3_instruct_270m": {
+        "model": gm.nn.Gemma3_270M,
+        "params": gm.ckpts.CheckpointPath.GEMMA3_270M_IT,
+    },
+    "gemma3_270m": {
+        "model": gm.nn.Gemma3_270M,
+        "params": gm.ckpts.CheckpointPath.GEMMA3_270M_PT,
+    },
     # 1B
     "gemma3_1b": {
         "model": gm.nn.Gemma3_1B,
@@ -493,7 +502,6 @@ def validate_output(
         params=flax_params,
         multi_turn=False,
         cache_length=256 if length <= 256 else 512,
-        # max_out_length=length,
     )
     flax_output = flax_sampler.chat(input_str, images=image)
     print("🔶 Flax output:", flax_output)
@@ -508,11 +516,11 @@ def main(_):
     assert preset in presets, (
         f"Invalid preset {preset}. Must be one of {','.join(presets)}"
     )
-    text_only = "text" in preset or "1b" in preset
+    text_only = "text" in preset or "1b" in preset or "270m" in preset
 
     print("🏃 Loading Flax model and tokeniser")
     flax_kwargs = {}
-    if text_only and "1b" not in preset:
+    if text_only and "1b" not in preset and "270m" not in preset:
         flax_kwargs["text_only"] = True
     flax_model = PRESET_MAP[preset]["model"](**flax_kwargs)
     flax_config = flax_model.config