[Android] No "Sending" status on messages.

When I send a message, after pressing the send button, there is period of time where the message is missing.
I presume that is because the server hasn't responded to say it received the message. (My internet is very slow and this can take up to a minute some times.)

No file or test is named in the issue. Start by tracing the Android message-send flow and how messages are rendered while waiting for the server response. Done means a sent message remains visible with a Sending status until the response arrives, including during slow connectivity.

Written by the indexing model from the issue text.