chat-view: Update file upload button on state change

For SMS/MMS chats, the ability to upload files depends on
whether mmsdtng is available or not which can often change
with change in hardware (eg: hardware buttons engaged on L5).

So update file upload button visibility on account state changes
so that actively open chat shall have the right file upload state
8 jobs for wip/sadiq/fix-active-mms-file-upload in 13 minutes and 34 seconds