refactor(app): Optimize shared settings using ProGuard

This commit adds a ProGuard rule to assume no side effects for the constructors of classes in the `app.revanced.extension.shared.settings` package.
This allows R8 to potentially optimize the app by removing these constructor calls if they are deemed unused or redundant during the optimization process.

Author: chsbuffer

app/proguard-rules.pro

@@ -23,4 +23,8 @@
 
 # If you keep the line number information, uncomment this to
 # hide the original source file name.
-#-renamesourcefileattribute SourceFile
+#-renamesourcefileattribute SourceFile
+
+-assumenosideeffects class app.revanced.extension.shared.settings.* {
+    public <init>(...);
+}