Don't rely on default locale when using toUpperCase() and toLowerCase()
Otherwise these methods may produce unexpected results if used for
strings that are intended to be interpreted locale independently.
Examples are programming language identifiers, protocol keys, and HTML
tags. For instance, "TITLE".toLowerCase() in a Turkish locale returns
"t\u0131tle", where '\u0131' is the LATIN SMALL LETTER DOTLESS I
character.
See
https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#toLowerCase--
http://blog.thetaphi.de/2012/07/default-locales-default-charsets-and.html
Bug: 511238
Change-Id: I5619ce1bde33d6ce2469506a915af9203bae0314
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>