[Flatpak] can't create PWA - write acces issue

[MetotoSakamoto]

Description

Flatpak can't create PWA

Steps to Reproduce

1. on top left corner, personnalize button > more tools > create shortcut > check "open in new window" > create

Actual result:

![bugBraveFlatpakPWA](https://user-images.githubusercontent.com/16877755/115972203-3e3a3900-a54d-11eb-8eda-45fdb19b9cb3.png

Expected result:

to have the icon of the newly PWA on the gnome shell application launcher

Reproduces how often:

allways

Brave version (brave://version info)

Brave 1.23.73 Chromium: 90.0.4430.85 (Build officiel) unknown (64 bits) Révision 5bc145d831c180d9ff94f29a0d7a2e1cbd30ef36-refs/branch-heads/4430@{#1311} Système d'exploitation Linux JavaScript V8 9.0.257.19 Agent utilisateur Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.85 Safari/537.36 Ligne de commande /app/brave/brave --enable-dom-distiller --disable-domain-reliability --no-pings --extension-content-verification=enforce_strict --extensions-install-verification=enforce --origin-trial-public-key=bYUKPJoPnCxeNvu72j4EmPuK7tr1PAC7SHh8ld9Mw3E=,fMS4mpO6buLQ/QMd+zJmxzty/VQ6B1EUZqoCU04zoRU= --sync-url=https://sync-v2.brave.com/v2 --lso-url=https://no-thanks.invalid --variations-server-url=https://variations.brave.com/seed --enable-features=PrefetchPrivacyChanges,WebUIDarkMode,LegacyTLSEnforced,DnsOverHttps,PasswordImport,ReducedReferrerGranularity,AutoupgradeMixedContent,SafetyTip --disable-features=AutofillEnableAccountWalletStorage,IdleDetection,TabHoverCards,TextFragmentAnchor,SignedExchangePrefetchCacheForNavigations,SubresourceWebBundles,SignedExchangeSubresourcePrefetch,SafeBrowsingEnhancedProtection,NetworkTimeServiceQuerying,LangClientHintHeader,NotificationTriggers,WebOTP,DirectSockets,SharingQRCodeGenerator,AutofillServerCommunication,SafeBrowsingEnhancedProtectionMessageInInterstitials,BraveDomainBlock --flag-switches-begin --flag-switches-end Chemin d'accès exécutable /app/brave/brave Chemin d'accès au profil /home/user/.var/app/com.brave.Browser/config/BraveSoftware/Brave-Browser/Default

Version/Channel Information:

on last update for sur

Other Additional Information:

Does't work even if I add via flatseal permission acces to ~/.local/share/applications & ~/.local/share/icons

Miscellaneous Information:

I don't know if it's relevant but I like chocapics

[fmarier]

I assume you are using the unofficial Flatpak. If so, I'd suggest you file this issue on their tracker: https://github.com/flathub/com.brave.Browser/issues