Ensure installed migrations comply with rubocop-rails-omakase

Adds space inside array literal brackets in ActiveStorage/ActionText migrations.

The new `rubocop-rails-omakase` enables `Layout/SpaceInsideArrayLiteralBrackets`,
which failed on the migrations created when installing ActiveStorage and ActionText.

Author: zachasme

actiontext/db/migrate/20180528164100_create_action_text_tables.rb

@@ -20,6 +20,6 @@ def primary_and_foreign_key_types
       setting = config.options[config.orm][:primary_key_type]
       primary_key_type = setting || :primary_key
       foreign_key_type = setting || :bigint
-      [primary_key_type, foreign_key_type]
+      [ primary_key_type, foreign_key_type ]
     end
 end

activestorage/db/migrate/20170806125915_create_active_storage_tables.rb

@@ -51,6 +51,6 @@ def primary_and_foreign_key_types
       setting = config.options[config.orm][:primary_key_type]
       primary_key_type = setting || :primary_key
       foreign_key_type = setting || :bigint
-      [primary_key_type, foreign_key_type]
+      [ primary_key_type, foreign_key_type ]
     end
 end