Remove pre-request-validation from v2 image_client

Glance v2 API provides Json-Schema definition for body format
of request, and clients can use it for pre-validation before
sending a request.
On service clients, this definition was used but this patch
removes these pre-validation code, because service clients
should be simple as possible for easy debugging.

Partially implements blueprint consistent-service-method-names

Change-Id: I114102ff4216683ecb06c5dd2c3f76911e792f90
1 file changed