fix: workaround for the client config streaming settings are not respected (#983)

a2a/src/main/java/com/google/adk/a2a/agent/RemoteA2AAgent.java

@@ -117,7 +117,7 @@ private RemoteA2AAgent(Builder builder) {
     if (this.description.isEmpty() && this.agentCard.description() != null) {
       this.description = this.agentCard.description();
     }
-    this.streaming = this.agentCard.capabilities().streaming();
+    this.streaming = builder.streaming && this.agentCard.capabilities().streaming();
   }
 
   public static Builder builder() {
@@ -133,6 +133,13 @@ public static class Builder {
     private List<? extends BaseAgent> subAgents;
     private List<Callbacks.BeforeAgentCallback> beforeAgentCallback;
     private List<Callbacks.AfterAgentCallback> afterAgentCallback;
+    private boolean streaming;
+
+    @CanIgnoreReturnValue
+    public Builder streaming(boolean streaming) {
+      this.streaming = streaming;
+      return this;
+    }
 
     @CanIgnoreReturnValue
     public Builder name(String name) {
@@ -181,6 +188,10 @@ public RemoteA2AAgent build() {
     }
   }
 
+  public boolean isStreaming() {
+    return streaming;
+  }
+
   private Message.Builder newA2AMessage(Message.Role role, List<io.a2a.spec.Part<?>> parts) {
     return new Message.Builder().messageId(UUID.randomUUID().toString()).role(role).parts(parts);
   }

a2a/src/test/java/com/google/adk/a2a/agent/RemoteA2AAgentTest.java

@@ -113,6 +113,20 @@ public void setUp() {
             .build();
   }
 
+  @Test
+  public void createAgent_streaming_false_returnsNonStreamingAgent() {
+    // With streaming false, the agent should not stream even if the AgentCard supports streaming.
+    RemoteA2AAgent agent = getAgentBuilder().streaming(false).build();
+    assertThat(agent.isStreaming()).isFalse();
+  }
+
+  @Test
+  public void createAgent_streaming_true_returnsStreamingAgent() {
+    // With streaming true, the agent should support streaming if the AgentCard supports streaming.
+    RemoteA2AAgent agent = getAgentBuilder().streaming(true).build();
+    assertThat(agent.isStreaming()).isTrue();
+  }
+
   @Test
   public void runAsync_aggregatesPartialEvents() {
     RemoteA2AAgent agent = createAgent();
@@ -763,7 +777,7 @@ private RemoteA2AAgent.Builder getAgentBuilder() {
   }
 
   private RemoteA2AAgent createAgent() {
-    return getAgentBuilder().build();
+    return getAgentBuilder().streaming(true).build();
   }
 
   @SuppressWarnings("unchecked") // cast for Mockito