Fix mascot size on thinner displays

src/components/Intro/MascotIntroEnd.js

@@ -24,7 +24,7 @@ class MascotIntroEnd extends React.Component<null> {
         <Mascot
           style={{
             ...styles.center,
-            height: '80%',
+            width: '100%',
           }}
           emotion={MASCOT_STYLE.COOL}
           animated

src/components/Intro/MascotIntroWelcome.js

@@ -26,7 +26,7 @@ class MascotIntroWelcome extends React.Component<null> {
         <Mascot
           style={{
             ...styles.center,
-            height: '80%',
+            width: '100%',
           }}
           emotion={MASCOT_STYLE.NORMAL}
           animated