feat: Allow to get data larger than 2MB in AsyncStorage

Default Android cursor size is 2MB so we can not store entries larger
than 2MB by default. But backup feature store quickly more than 2MB.

There are two main possibilities :
- AsyncStorage recommand to separate data in multiple entries and use
multiGet and multiSet
- increase sCursorWindowSize in MainApplication.java

I try here the second way now which looks like the "easy quick fix".

50MB seems a reasonable value here. 1000 pictures in mediasToBackup ~
330KiB

See
react-native-async-storage/async-storage#617 (comment)
and
https://react-native-async-storage.github.io/async-storage/docs/limits

android/app/src/main/java/io/cozy/flagship/mobile/MainApplication.java

@@ -21,6 +21,9 @@
 import io.cozy.flagship.mobile.httpserver.HttpServerPackage;
 import io.cozy.flagship.mobile.webview.WebViewPackage;
 
+import android.database.CursorWindow;
+import java.lang.reflect.Field;
+
 public class MainApplication extends Application implements ReactApplication {
 
   private final ReactNativeHost mReactNativeHost =
@@ -61,6 +64,16 @@ public void onCreate() {
     initializeFlipper(this, getReactNativeHost().getReactInstanceManager());
     WebView.setWebContentsDebuggingEnabled(true);
     OkHttpClientProvider.setOkHttpClientFactory(new UserAgentClientFactory());
+
+    try {
+      Field field = CursorWindow.class.getDeclaredField("sCursorWindowSize");
+      field.setAccessible(true);
+      field.set(null, 50 * 1024 * 1024); // 50MB
+    } catch (Exception e) {
+      if (BuildConfig.DEBUG) {
+        e.printStackTrace();
+      }
+    }
   }
 
   /**