Fix Random LayoutInterfaceTest Failures in PHP 5.3

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Describe your issue or idea

We have some random failures coming from LayoutInterfaceTest in PHP 5.3 due to back-slashes in the title. We still have a JSON encoding problem in places but for now we should simply avoid this in our tests so we don't get random failures.

Fail      Other      layout.test       1240 LayoutInterfaceTest->testBlockUnins
"A testing block for layouts." found Exception ConfigStor config.inc        1041 ConfigFileStorage->read()          
The configuration file "layout.layout.tihrjljp" is not properly formatted JSON. Contents: { "_config_name": "layout.layout.tihrjljp", "path": "layout-test-path", "name": "tihrjljp", "title": "k\\\"m4k{ I","description":null,"module":null,"weight":0,"storage":1,"layout_template":"moscone_flipped","disabled":false,"settings":{"title":"","title_display":"default","title_block":null},"positions":{"header":["fddff427-8824-42ea-a408-8a2328467dd7","cd89f2e6-9e8d-4b42-a51f-31851bb3bab6"],"content":["83eb6f02-3fb6-4f74-ac00-c960901ced1b"],"footer":["8ee7b69e-3947-484c-a600-d0ec31547613"],"top":["48e8de5e-864e-4fb1-924d-777f76fe7225"]},"content":{"fddff427-8824-42ea-a408-8a2328467dd7":{"plugin":"system: header","data":{"module":"system","delta":"header","settings":{"title_display":"default","title":"","style":"default","block_settings":{"menu":"user-menu","logo":1,"site_name":1,"site_slogan":1},"contexts":[]},"uuid":"fddff427-8824-42ea-a408-8a2328467dd7","style":{"plugin":"default","data":{"settings":{"classes":""}}}}},"cd89f2e6-9e8d-4b42-a51f-31851bb3bab6":{"plugin":"system: 

From https://zen.ci/backdrop/backdrop/test/test-php53-backdrop_backdrop_2166-d6b349f-1

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Merged into 1.x and 1.9.x.