Bug 1736113: Normalize Firefox MSIX Package: Use 'App' as <Application Id> in AppxManifest.xml r=nalexander

This isn't strictly necessary, but 'App' is what most Apps seem to use, so we may as well too.

Also ensures 'en-US' is the first listed language, to make it the default.

Differential Revision: https://phabricator.services.mozilla.com/D132194

browser/app/winlauncher/LaunchUnelevated.cpp

@@ -145,10 +145,10 @@ LauncherVoidResult LaunchUnelevated(int aArgc, wchar_t* aArgv[]) {
   UniquePtr<wchar_t[]> packageFamilyName = mozilla::GetPackageFamilyName();
   if (packageFamilyName) {
     int cmdLen =
-        // 26 for the prefix + suffix + null terminator below
-        26 + wcslen(packageFamilyName.get());
+        // 22 for the prefix + suffix + null terminator below
+        22 + wcslen(packageFamilyName.get());
     wchar_t appCmd[cmdLen];
-    swprintf(appCmd, cmdLen, L"shell:appsFolder\\%s!FIREFOX",
+    swprintf(appCmd, cmdLen, L"shell:appsFolder\\%s!App",
              packageFamilyName.get());
     cmd = appCmd;
   } else {

browser/installer/windows/msix/AppxManifest.xml.in

@@ -24,7 +24,7 @@
     <rescap:Capability Name="runFullTrust" />
   </Capabilities>
   <Applications>
-    <Application Id="FIREFOX" Executable="VFS\ProgramFiles\@APPX_INSTDIR@\@MOZ_APP_NAME@.exe" EntryPoint="Windows.FullTrustApplication">
+    <Application Id="App" Executable="VFS\ProgramFiles\@APPX_INSTDIR@\@MOZ_APP_NAME@.exe" EntryPoint="Windows.FullTrustApplication">
       <uap:VisualElements BackgroundColor="#20123A" DisplayName="@MOZ_APP_DISPLAYNAME@" Square150x150Logo="Assets\Square150x150Logo.png" Square44x44Logo="Assets\Square44x44Logo.png" Description="@MOZ_APP_DISPLAYNAME@">
         <uap:DefaultTile Wide310x150Logo="Assets\Wide310x150Logo.png" Square310x310Logo="Assets\LargeTile.png" Square71x71Logo="Assets\SmallTile.png" />
       </uap:VisualElements>

python/mozbuild/mozbuild/repackaging/msix.py

@@ -610,7 +610,7 @@ def repackage_msix(
 
     locales = ["en-US"] + list(sorted(locales))
     resource_language_list = "\n".join(
-        f'    <Resource Language="{locale}" />' for locale in sorted(locales)
+        f'    <Resource Language="{locale}" />' for locale in locales
     )
 
     defines = {