[TASK] Fix CGL violations against DoubleQuoteUsage

Change-Id: Ia82bb9e0da1761e42af8e32f85443c0a231173f7
Release: 6.0
Resolves: #38303
Reviewed-on: http://review.typo3.org/12291
Reviewed-by: Wouter Wolters
Reviewed-by: Philipp Gampe
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn