Add vertex ai autoconfig and spring boot

- Add Vertex AI Autoconfigurations for chat and embedding clients.
 - Factor out the embeding client dimensions() computation into an abstract parent AbstractEmbeddingClient.
 - Add ITs
 - Vertex dos.

embedding-clients/transformers-embedding/src/main/java/org/springframework/ai/embedding/TransformersEmbeddingClient.java

@@ -5,7 +5,6 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Collectors;
 
 import ai.djl.huggingface.tokenizers.Encoding;
@@ -35,7 +34,7 @@ import org.springframework.util.StringUtils;
  *
  * @author Christian Tzolov
  */
-public class TransformersEmbeddingClient implements EmbeddingClient, InitializingBean {
+public class TransformersEmbeddingClient extends AbstractEmbeddingClient implements InitializingBean {
 
 	private static final Log logger = LogFactory.getLog(TransformersEmbeddingClient.class);
 
@@ -72,8 +71,6 @@ public class TransformersEmbeddingClient implements EmbeddingClient, Initializin
 	 */
 	private OrtSession session;
 
-	private final AtomicInteger embeddingDimensions = new AtomicInteger(-1);
-
 	/**
 	 * Specifies what parts of the {@link Document}'s content and metadata will be used
 	 * for computing the embeddings. Applicable for the {@link #embed(Document)} method
@@ -148,10 +145,6 @@ public class TransformersEmbeddingClient implements EmbeddingClient, Initializin
 		this.modelResource = toResource(modelResourceUri);
 	}
 
-	public void setEmbeddingDimensions(int dimension) {
-		this.embeddingDimensions.set(dimension);
-	}
-
 	public void setModelOutputName(String modelOutputName) {
 		this.modelOutputName = modelOutputName;
 	}
@@ -325,14 +318,6 @@ public class TransformersEmbeddingClient implements EmbeddingClient, Initializin
 		return result;
 	}
 
-	@Override
-	public int dimensions() {
-		if (this.embeddingDimensions.get() < 0) {
-			this.embeddingDimensions.set(EmbeddingUtil.dimensions(this, "Test"));
-		}
-		return this.embeddingDimensions.get();
-	}
-
 	private static Resource toResource(String uri) {
 		return new DefaultResourceLoader().getResource(uri);
 	}