Don't write defaultFormat setting, use default value

Nowhere else does this (write a setting if it’s not set).

It took me a while to see that this code does not do what it intends,
because `defaultFormat` is already the default value in the first
`context.getString`, so calling `getMediaFormatFromKey` again is the
exact same call (“do you know the definition of insanity…”) and will
return `null` again …

So let’s drop the setting write and just rely on the default values.

Author: Profpatsch

app/src/main/java/org/schabi/newpipe/util/ListHelper.java

@@ -643,6 +643,7 @@ private static int getDefaultResolutionWithDefaultFormat(@NonNull final Context
                 context.getString(R.string.best_resolution_key), defaultFormat, videoStreams);
     }
 
+    @Nullable
     private static MediaFormat getDefaultFormat(@NonNull final Context context,
                                                 @StringRes final int defaultFormatKey,
                                                 @StringRes final int defaultFormatValueKey) {
@@ -651,18 +652,14 @@ private static MediaFormat getDefaultFormat(@NonNull final Context context,
 
         final String defaultFormat = context.getString(defaultFormatValueKey);
         final String defaultFormatString = preferences.getString(
-                context.getString(defaultFormatKey), defaultFormat);
+                context.getString(defaultFormatKey),
+                defaultFormat
+        );
 
-        MediaFormat defaultMediaFormat = getMediaFormatFromKey(context, defaultFormatString);
-        if (defaultMediaFormat == null) {
-            preferences.edit().putString(context.getString(defaultFormatKey), defaultFormat)
-                    .apply();
-            defaultMediaFormat = getMediaFormatFromKey(context, defaultFormat);
-        }
-
-        return defaultMediaFormat;
+        return getMediaFormatFromKey(context, defaultFormatString);
     }
 
+    @Nullable
     private static MediaFormat getMediaFormatFromKey(@NonNull final Context context,
                                                      @NonNull final String formatKey) {
         MediaFormat format = null;