I have finally solved the problem by looking at sources of Azure API Java SDK
It is just purely documented x-ms-file-rename-source. In the sources we can see that the value should be "the URI-style path of the source file, up to 2 KB in length."
In caseof SAS authentication the URI should include SAS token as well.
This must be written in the documentation for Rename File request in REST API documentation! The current page contains very confusing explanation and has no any examples.