SeriesGroupBy corr and cov do not raise the expected error at pipeline construction time

SeriesGroupBy.corr should raise an error at construction time because it needs multiple Series:

```

In [4]: df.groupby('A').B.corr()
---------------------------------------------------------------------------
TypeError
Traceback (most recent call last)
in

----> 1 df.groupby('A').B.corr()

~/.pyenv/versions/3.8.6/envs/beam/lib/python3.8/site-packages/pandas/core/groupby/groupby.py
in wrapper(*args, **kwargs)
815 return self.apply(curried)
816
--> 817
return self._python_apply_general(curried, self._obj_with_exclusions)
818
819
wrapper.__name__ = name

~/.pyenv/versions/3.8.6/envs/beam/lib/python3.8/site-packages/pandas/core/groupby/groupby.py
in _python_apply_general(self, f, data)
926 data after applying f
927
"""
--> 928 keys, values, mutated = self.grouper.apply(f, data, self.axis)
929
930
return self._wrap_applied_output(

~/.pyenv/versions/3.8.6/envs/beam/lib/python3.8/site-packages/pandas/core/groupby/ops.py
in apply(self, f, data, axis)
236 # group might be modified
237 group_axes
= group.axes
--> 238 res = f(group)
239 if not _is_indexed_like(res, group_axes,
axis):
240 mutated = True

~/.pyenv/versions/3.8.6/envs/beam/lib/python3.8/site-packages/pandas/core/groupby/groupby.py
in curried(x)
804
805 def curried(x):
--> 806 return f(x, *args,
**kwargs)
807
808 # preserve the name so we can detect it when calling plot methods,

TypeError:
corr() missing 1 required positional argument: 'other'

```

But this isn't raised when called on an empty dataset (perhaps an upstream bug), so we don't raise it during proxy generation. It will not fail until the pipeline is running.

Imported from Jira [BEAM-12367](https://issues.apache.org/jira/browse/BEAM-12367). Original Jira may contain additional context.
Reported by: bhulette.