Fix duplicate check

Author: adinauer

sentry/src/main/java/io/sentry/featureflags/FeatureFlagBuffer.java

@@ -45,7 +45,8 @@ public void add(final @Nullable String flag, final @Nullable Boolean result) {
     try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
       final int size = flags.size();
       for (int i = 0; i < size; i++) {
-        if (flags.get(i).equals(flag)) {
+        final @NotNull FeatureFlagEntry entry = flags.get(i);
+        if (entry.flag.equals(flag)) {
           flags.remove(i);
           break;
         }