Bug 1697331 - Set NSRequiresAquaSystemAppearance to false for the parent process and the updater. r=mac-reviewers,bradwerth

We have four instances of NSRequiresAquaSystemAppearance <true/> in the tree; this fixes two out of four:

 - The parent process is now protected by the widget.macos.require-system-appearance pref.
 - The updater never shows any UI, and if it does, it's probably using native controls which correctly adapt to Dark Mode.
 - We cannot yet flip the switch for content processes (ipc/app/macbuild/Contents/Info.plist.in) as long as we still allow using the native theme in content processes, due to bug 1688113.
 - And the crash reporter is tracked in bug 1697991.

Depends on D107749

Differential Revision: https://phabricator.services.mozilla.com/D108150

browser/app/macbuild/Contents/Info.plist.in

@@ -243,7 +243,7 @@
   <key>NSSupportsAutomaticGraphicsSwitching</key>
   <true/>
   <key>NSRequiresAquaSystemAppearance</key>
-  <true/>
+  <false/>
   <key>NSPrincipalClass</key>
   <string>GeckoNSApplication</string>
 	<key>SMPrivilegedExecutables</key>

toolkit/mozapps/update/updater/macbuild/Contents/Info.plist.in

@@ -27,7 +27,7 @@
 	<key>NSMainNibFile</key>
 	<string>MainMenu</string>
 	<key>NSRequiresAquaSystemAppearance</key>
-	<true/>
+	<false/>
 	<key>NSPrincipalClass</key>
 	<string>NSApplication</string>
 	<key>LSUIElement</key>