Fix forbidden APIs

Signed-off-by: Atri Sharma <atri.jiit@gmail.com>

Author: atris

server/src/main/java/org/opensearch/search/query/StreamingScoringMode.java

@@ -49,7 +49,7 @@ public static StreamingScoringMode fromString(String mode) {
         if (mode == null) {
             return DEFAULT;
         }
-        switch (mode.toLowerCase()) {
+        switch (mode.toLowerCase(java.util.Locale.ROOT)) {
             case "none":
             case "no_scoring":
                 return NO_SCORING;

server/src/main/java/org/opensearch/search/streaming/StreamingSearchSettings.java

@@ -216,7 +216,7 @@ public final class StreamingSearchSettings {
         "search.streaming.score_mode",
         "COMPLETE",
         value -> {
-            if (!Arrays.asList("COMPLETE", "TOP_SCORES", "MAX_SCORE").contains(value.toUpperCase())) {
+            if (!Arrays.asList("COMPLETE", "TOP_SCORES", "MAX_SCORE").contains(value.toUpperCase(java.util.Locale.ROOT))) {
                 throw new IllegalArgumentException("Invalid score mode: " + value);
             }
         },