refactor: amend millis to ms in timeoutMessage

Author: AlessandroMiccoli

src/main/java/io/appium/java_client/AppiumFluentWait.java

@@ -263,7 +263,7 @@ private <V> void handleTimeoutException(Throwable lastException, Function<? supe
                 .orElseGet(() -> "waiting for " + isTrue);
 
         var timeoutMessage = String.format(
-                "Expected condition failed: %s (tried for %s millis with an interval of %s millis)",
+                "Expected condition failed: %s (tried for %s ms with an interval of %s ms)",
                 message,
                 getTimeout().toMillis(),
                 getInterval().toMillis()