Fix a false positive for Style/Alias

[koic]

This PR fixes the following false positive to prevent incorrect autocorrection for Style/Alias when EncforcedStyle: prefer_alias and using alias with interpolated symbol argument:

$ ruby -ce 'alias :"string#{interpolation}" :symbol'
Syntax OK

$ echo 'alias :"string#{interpolation}" :symbol' | bundle exec rubocop --stdin example.rb -a --only Style/Alias
Inspecting 1 file
F

Offenses:

example.rb:1:7: F: Lint/Syntax: unexpected token tSTRING_BEG
(Using Ruby 2.7 parser; configure using TargetRubyVersion parameter, under AllCops)
alias "string#{interpolation}" symbol
      ^
example.rb:1:7: C: [Corrected] Style/Alias: Use alias "string#{interpolation}" symbol instead of alias :"string#{interpolation}" :symbol.
alias :"string#{interpolation}" :symbol
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
example.rb:1:32: F: Lint/Syntax: unexpected token tIDENTIFIER
(Using Ruby 2.7 parser; configure using TargetRubyVersion parameter, under AllCops)
alias "string#{interpolation}" symbol
                               ^^^^^^

1 file inspected, 3 offenses detected, 1 offense corrected
====================
alias "string#{interpolation}" symbol

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