Allow larger read cache

app/src/main/java/com/hippo/ehviewer/EhApplication.kt

@@ -258,7 +258,7 @@ class EhApplication : Application(), DefaultLifecycleObserver, ImageLoaderFactor
         val imageCache by lazy {
             DiskCache.Builder().apply {
                 directory(application.cacheDir.toOkioPath() / "image_cache")
-                maxSizeBytes(Settings.readCacheSize.coerceIn(40, 1280).toLong() * 1024 * 1024)
+                maxSizeBytes(Settings.readCacheSize.coerceIn(320, 5120).toLong() * 1024 * 1024)
             }.build()
         }
     }

app/src/main/res/values/arrays.xml

@@ -148,12 +148,11 @@
     </string-array>
 
     <string-array name="read_cache_size_entry_values" translatable="false">
-        <item>40</item>
-        <item>80</item>
-        <item>160</item>
         <item>320</item>
         <item>640</item>
         <item>1280</item>
+        <item>2560</item>
+        <item>5120</item>
     </string-array>
 
     <string-array name="filter_entries">