Fix different types in rsub caused bug (#15707)
Summary:
Before this pr, rsub did not convert two elements into the same dtype, therefore "1 - x" may export to an onnx model that two elements of rsub having different dtype.
By adding this symbolic patch this bug should be fixed.
Related test cases also created.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15707
Differential Revision: D13583042
Pulled By: zrphercule
fbshipit-source-id: 3a2de47a1a8d1ded1a0adfb911adbe6ac729cdef
