Bug 34403: Disable Normal mode by default

app/src/main/java/org/mozilla/fenix/HomeActivity.kt

...ain/java/org/mozilla/fenix/browser/BaseBrowserFragment.kt

...rg/mozilla/fenix/components/toolbar/DefaultToolbarMenu.kt

app/src/main/java/org/mozilla/fenix/home/HomeFragment.kt

app/src/main/java/org/mozilla/fenix/home/HomeMenu.kt

.../main/java/org/mozilla/fenix/settings/SettingsFragment.kt

app/src/main/java/org/mozilla/fenix/tabtray/TabTrayView.kt

app/src/main/java/org/mozilla/fenix/utils/Settings.kt

app/src/main/res/navigation/nav_graph.xml

app/src/main/res/values/preference_keys.xml

app/src/main/res/values/torbrowser_strings.xml

app/src/main/res/xml/preferences.xml

app/src/main/res/xml/private_browsing_preferences.xml

app/src/test/java/org/mozilla/fenix/utils/SettingsTest.kt