Remove breaking abstract isUTC() getter from Rounding.java.

Signed-off-by: Finn Carroll <carrofin@amazon.com>

server/src/main/java/org/opensearch/common/Rounding.java

@@ -275,6 +275,14 @@ public DateTimeUnit unit() {
         return null;
     }
 
+    /**
+     * Helper function for checking if the time zone requested for date histogram
+     * aggregation is utc or not
+     */
+    public boolean isUTC() {
+        throw new UnsupportedOperationException();
+    }
+
     /**
      * A strategy for rounding milliseconds since epoch.
      *
@@ -1429,10 +1437,4 @@ public static OptionalLong getInterval(Rounding rounding) {
 
         return OptionalLong.of(interval);
     }
-
-    /**
-     * Helper function for checking if the time zone requested for date histogram
-     * aggregation is utc or not
-     */
-    public abstract boolean isUTC();
 }