Indices API: fixes GET Alias API backwards compatibility

For just the case when only the aliases are requested, the default indices options are to ignore missing indexes. When requesting any other feature or any combination of features, the default will be to error on missing indices.

Closes #7793
@clintongormley pointed out that in 1.3.1 if you call `/_aliases` it will return both open and closed indices, but if you call `/foo*/_aliases` it will only expand to open indices. This if statement is providing that behaviour