Add force_f32 option in go & C api for better quality on gpu backend

LiteRT-LM-PiperOrigin-RevId: 860635677

Author: protobird-git

c/engine.cc

@@ -315,6 +315,14 @@ void litert_lm_engine_settings_enable_benchmark(
   }
 }
 
+void litert_lm_engine_settings_set_activation_data_type(
+    LiteRtLmEngineSettings* settings, int activation_data_type_int) {
+  if (settings && settings->settings) {
+    settings->settings->GetMutableMainExecutorSettings().SetActivationDataType(
+      static_cast<litert::lm::ActivationDataType>(activation_data_type_int));
+  }
+}
+
 LiteRtLmEngine* litert_lm_engine_create(
     const LiteRtLmEngineSettings* settings) {
   if (!settings || !settings->settings) {

c/engine.h

@@ -186,6 +186,16 @@ LITERT_LM_C_API_EXPORT
 void litert_lm_engine_settings_set_cache_dir(LiteRtLmEngineSettings* settings,
                                              const char* cache_dir);
 
+// Sets the activation data type.
+//
+// @param settings The engine settings.
+// @param activation_data_type_int The activation data type. See
+// `ActivationDataType` in executor_settings_base.h for the possible values
+// (e.g., 0 for F32, 1 for F16, 2 for I16, 3 for I8).
+LITERT_LM_C_API_EXPORT
+void litert_lm_engine_settings_set_activation_data_type(
+    LiteRtLmEngineSettings* settings, int activation_data_type_int);
+
 // Enables benchmarking for the engine.
 //
 // @param settings The engine settings.