Default to downloading as CBZ (closes #6942)

Generally seems fine. People with weak devices may experience some issues, but they can toggle it off/extract the archives separately if needed.

(cherry picked from commit 883945e3e8b4c3fe5ec1bb151c247db7404b037c)

app/src/main/java/eu/kanade/tachiyomi/data/preference/PreferencesHelper.kt

@@ -204,7 +204,7 @@ class PreferencesHelper(val context: Context) {
 
     fun downloadOnlyOverWifi() = prefs.getBoolean(Keys.downloadOnlyOverWifi, true)
 
-    fun saveChaptersAsCBZ() = flowPrefs.getBoolean("save_chapter_as_cbz", false)
+    fun saveChaptersAsCBZ() = flowPrefs.getBoolean("save_chapter_as_cbz", true)
 
     fun folderPerManga() = prefs.getBoolean(Keys.folderPerManga, false)