Configure the {@link ContentTypeResolver} to use to resolve the content
type of an input message.
<p>Note that if no resolver is configured, then
{@link #setStrictContentTypeMatch() strictContentTypeMatch} should
be left as {@code false} (the default) or otherwise this converter will
ignore all messages.
<p>By default, a {@code DefaultContentTypeResolver} instance is used.
Configure the {@link ContentTypeResolver} to use to resolve the content type of an input message. <p>Note that if no resolver is configured, then {@link #setStrictContentTypeMatch() strictContentTypeMatch} should be left as {@code false} (the default) or otherwise this converter will ignore all messages. <p>By default, a {@code DefaultContentTypeResolver} instance is used.