Avoid using ' in app/src/main/res/values/torbrowser_strings.xml (fenix)

In https://gitweb.torproject.org/translation-tools.git/commit/?id=f0160f12407cb019bbaf680c9aded208181281c2 we added a check for unescaped ' in fenix translation files. However since we're just using grep and not a real xml parser, it does not ignore comment lines, and we have an error we the line <!-- LOCALIZATION NOTE (yec2022_donation_matching): Please translate the 'Friends of Tor' phrase, but.

To avoid this I think we can use " instead of ' in the LOCALIZATION NOTE.