Java 17 features (#15493)

- add missing @override
- Java style array syntax
- remove redundant modifiers
- always move String constants to left side in comparisons
- simplify lambda expressions and return statements
- use replace instead of replaceAll w/o regex

Signed-off-by: Holger Friedrich <mail@holger-friedrich.de>

bundles/org.openhab.voice.voicerss/src/main/java/org/openhab/voice/voicerss/tool/CreateTTSCache.java

@@ -46,7 +46,7 @@ public class CreateTTSCache {
             usage();
             return RC_USAGE;
         }
-        if (!args[0].equalsIgnoreCase("--api-key")) {
+        if (!"--api-key".equalsIgnoreCase(args[0])) {
             usage();
             return RC_API_KEY_MISSING;
         }