rn,tile-view: render a larger avatar in tile view mode

react/features/filmstrip/components/native/Thumbnail.js

             touchFeedback = { false }>
 
             <ParticipantView
-                avatarSize = { AVATAR_SIZE }
+                avatarSize = { tileView ? AVATAR_SIZE * 1.5 : AVATAR_SIZE }
                 disableVideo = { isScreenShare || participant.isFakeParticipant }
                 participantId = { participantId }
                 style = { _styles.participantViewStyle }