Fix test runner test when the parallelization output is show

Those tests are broken since ecc5afe.
I'm not sure why they are not broken on CI though.

Author: rafaelfranca

railties/test/application/test_runner_test.rb

@@ -745,7 +745,7 @@ def test_running_with_ruby_gets_test_env_by_default
 
       file = create_test_for_env("test")
       results = Dir.chdir(app_path) {
-        `ruby -Ilib:test #{file}`.each_line.map { |line| JSON.parse line }
+        `ruby -Ilib:test #{file}`.each_line.filter_map { |line| JSON.parse(line) if line.start_with?("{") }
       }
       assert_equal 1, results.length
       failures = results.first["failures"]
@@ -762,7 +762,8 @@ def test_running_with_ruby_can_set_env_via_cmdline
 
       file = create_test_for_env("development")
       results = Dir.chdir(app_path) {
-        `RAILS_ENV=development ruby -Ilib:test #{file}`.each_line.map { |line| JSON.parse line }
+        `RAILS_ENV=development ruby -Ilib:test #{file}`.each_line.
+          filter_map { |line| JSON.parse(line) if line.start_with?("{") }
       }
       assert_equal 1, results.length
       failures = results.first["failures"]