Change registration field placeholder from 'Your name' to 'User name'
Change registration field placeholder from 'Your name' to 'User name'

Signed-off-by: Thanos Lefteris <c1aaafefa5e5eb338a07115696c553c656221d9f@gmail.com>

vector-im/riot-android,riot-spanish/riot-android,floviolleau/vector-android,vector-im/vector-android,vt0r/vector-android,floviolleau/vector-android,vector-im/vector-android,vt0r/vector-android,noepitome/neon-android,vt0r/vector-android,vector-im/vector-android,floviolleau/vector-android,vector-im/vector-android,vector-im/riot-android,vector-im/riot-android,vector-im/riot-android,noepitome/neon-android,riot-spanish/riot-android,riot-spanish/riot-android,vector-im/riot-android,noepitome/neon-android,riot-spanish/riot-android,noepitome/neon-android