Inconsistent constructor visibility of the TitanChatBedrockApi class

[codebyjakob]

The constructor

TitanChatBedrockApi(String modelId, String region) {
  super(modelId, region);
}

of the TitanChatBedrockApi class is currently package-private and not accessible as a user of the library.

The corresponding other [...]Api class constructors of the bedrock clients are public.

I assume this should be public as well.