Mock endpoint - Should reset StreamCache when evaluating expecations

See
http://camel.465427.n5.nabble.com/Setting-multiple-expectations-when-streamCaching-is-on-tp5815400.html

When using stream caching then you may have 2+ expecations on mock endpoints that work on the message body. And then on the 2nd+ it may fail due the stream cache has not been reset, so the message body can be read from the beginning.