Use Locale.ROOT for locale neutral, case insensitive comparisons

[HasiniSama]

Purpose

$subject

Changed

• toUpperCase() --> toUpperCase(Locale.ROOT)
• toLowerCase() --> toLowerCase(Locale.ROOT)
• toLowerCase(Locale.English) --> toLowerCase(Locale.ROOT)
• Locale.English --> Locale.ROOT

Ported from:

• spring-projects@23656ae
• spring-projects@c765d03
• spring-projects@11d4272

Additional files changed:

• spring-web/src/test/java/org/springframework/http/client/AbstractAsyncHttpRequestFactoryTests.java - file not found in master or original commits
• spring-web/src/main/java/org/springframework/remoting/httpinvoker/HttpComponentsHttpInvokerRequestExecutor.java - file not found in master or original commits
• spring-web/src/main/java/org/springframework/remoting/httpinvoker/SimpleHttpInvokerRequestExecutor.java - file not found in master or original commits
• spring-webflux/src/main/java/org/springframework/web/reactive/resource/GzipResourceResolver.java - file not found in master or original commits
• spring-webmvc/src/main/java/org/springframework/web/servlet/resource/GzipResourceResolver.java - file not found in master or original commits
• spring-context/src/main/java/org/springframework/scheduling/support/CronSequenceGenerator.java - file not found in master or original commits
• spring-websocket/src/main/java/org/springframework/web/socket/sockjs/transport/session/AbstractSockJsSession.java - method not found in master or original commits
• spring-web/src/main/java/org/springframework/web/server/adapter/HttpWebHandlerAdapter.java - method not found in master or original commits

[sadilchamishka]

Ported from - spring-projects@11d4272