FullScreenLoading: Center LoadingIndicator vertically in the whole screen

Not just in the area below the top inset, or, when the offline
notice is shown, the top inset and the offline notice.

The spinner graphic isn't nearly big enough to run afoul of any of
the insets or the offline notice.

Author: chrisbobbe

src/common/FullScreenLoading.js

@@ -2,12 +2,10 @@
 import React from 'react';
 import type { Node } from 'react';
 import { View } from 'react-native';
-import { useSafeAreaInsets } from 'react-native-safe-area-context';
 
 import { BRAND_COLOR, createStyleSheet } from '../styles';
 import LoadingIndicator from './LoadingIndicator';
 import ZulipStatusBar from './ZulipStatusBar';
-import { OfflineNoticePlaceholder } from '../boot/OfflineNoticeProvider';
 
 const componentStyles = createStyleSheet({
   center: {
@@ -24,19 +22,16 @@ type Props = $ReadOnly<{||}>;
  * Meant to be used to cover the whole screen.
  */
 export default function FullScreenLoading(props: Props): Node {
-  const insets = useSafeAreaInsets();
-
   return (
     <>
       <ZulipStatusBar backgroundColor={BRAND_COLOR} />
+      {
+        // No need for `OfflineNoticePlaceholder` here: the content, a
+        // loading indicator centered on the whole screen, isn't near the
+        // top of the screen, so it doesn't need protection from being
+        // hidden under the offline notice.
+      }
       <View style={componentStyles.center}>
-        <View
-          style={{
-            height: insets.top,
-            backgroundColor: BRAND_COLOR,
-          }}
-        />
-        <OfflineNoticePlaceholder />
         <LoadingIndicator color="black" size={80} showLogo />
       </View>
     </>