Updates the math and interop samples to use the fully-qualified method name.

This bring the ruby GRPC up-to-date with the changes in []
TESTED: math client access math server OK, similarly the passing interop tests continue to pass
	Change on 2015/01/08 by temiola <temiola@google.com>
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=83527704