fix: reduce avatar font size

react/features/base/avatar/components/native/styles.js

     initialsText: (size: number = DEFAULT_SIZE) => {
         return {
             color: 'rgba(255, 255, 255, 0.6)',
-            fontSize: size * 0.5,
+            fontSize: size * 0.45,
             fontWeight: '100'
         };
     },