feat: Support RealtimeInputConfig, and language_code in SpeechConfig in python

Fix system instruction in LiveConnectConfig

PiperOrigin-RevId: 745819825

Author: yinghsienwu

examples/src/main/java/com/google/genai/examples/LiveAudioConversationAsync.java

@@ -154,6 +154,7 @@ public static void main(String[] args) throws LineUnavailableException {
                             .prebuiltVoiceConfig(
                                 PrebuiltVoiceConfig.builder().voiceName(voiceName).build())
                             .build())
+                    .languageCode("en-US")
                     .build())
             .build();
 

src/main/java/com/google/genai/Models.java

@@ -534,6 +534,13 @@ ObjectNode SpeechConfigToMldev(
               toObject));
     }
 
+    if (Common.getValueByPath(fromObject, new String[] {"languageCode"}) != null) {
+      Common.setValueByPath(
+          toObject,
+          new String[] {"languageCode"},
+          Common.getValueByPath(fromObject, new String[] {"languageCode"}));
+    }
+
     return toObject;
   }
 
@@ -1666,6 +1673,13 @@ ObjectNode SpeechConfigToVertex(
               toObject));
     }
 
+    if (Common.getValueByPath(fromObject, new String[] {"languageCode"}) != null) {
+      Common.setValueByPath(
+          toObject,
+          new String[] {"languageCode"},
+          Common.getValueByPath(fromObject, new String[] {"languageCode"}));
+    }
+
     return toObject;
   }
 

src/main/java/com/google/genai/types/SpeechConfig.java

@@ -33,6 +33,12 @@ public abstract class SpeechConfig extends JsonSerializable {
   @JsonProperty("voiceConfig")
   public abstract Optional<VoiceConfig> voiceConfig();
 
+  /**
+   * Language code (ISO 639. e.g. en-US) for the speech synthesization. Only available for Live API.
+   */
+  @JsonProperty("languageCode")
+  public abstract Optional<String> languageCode();
+
   /** Instantiates a builder for SpeechConfig. */
   public static Builder builder() {
     return new AutoValue_SpeechConfig.Builder();
@@ -53,6 +59,9 @@ private static Builder create() {
     @JsonProperty("voiceConfig")
     public abstract Builder voiceConfig(VoiceConfig voiceConfig);
 
+    @JsonProperty("languageCode")
+    public abstract Builder languageCode(String languageCode);
+
     public abstract SpeechConfig build();
   }