Don't log AWS SDK stack trace, updates documentation

Signed-off-by: Christopher Miles <twitch@nervestaple.com>

Author: cmiles74

models/spring-ai-bedrock-converse/src/main/java/org/springframework/ai/bedrock/converse/BedrockProxyChatModel.java

@@ -807,7 +807,7 @@ private Builder() {
 this.region = DefaultAwsRegionProviderChain.builder().build().getRegion();
 }
 catch (SdkClientException e) {
-logger.warn("Failed to load region from DefaultAwsRegionProviderChain, using US_EAST_1", e);
+logger.warn("Failed to load region from DefaultAwsRegionProviderChain, using {}}", this.region);
 }
 }
 

spring-ai-docs/src/main/antora/modules/ROOT/pages/api/chat/bedrock-converse.adoc

@@ -73,7 +73,7 @@ The prefix `spring.ai.bedrock.aws` is the property prefix to configure the conne
 |====
 | Property | Description | Default
 
-| spring.ai.bedrock.aws.region | AWS region to use. | us-east-1
+| spring.ai.bedrock.aws.region | AWS region to use. | AWS SDK value or us-east-1
 | spring.ai.bedrock.aws.timeout | AWS timeout to use. | 5m
 | spring.ai.bedrock.aws.access-key | AWS access key. | -
 | spring.ai.bedrock.aws.secret-key | AWS secret key. | -
@@ -89,6 +89,8 @@ To enable, spring.ai.model.chat=bedrock-converse (It is enabled by default)
 To disable, spring.ai.model.chat=none (or any value which doesn't match bedrock-converse)
 
 This change is done to allow configuration of multiple models.
+
+The AWS SDK checks several places for the region, if none of these are set then "us-east-1" is used.
 ====
 
 The prefix `spring.ai.bedrock.converse.chat` is the property prefix that configures the chat model implementation for the Converse API.