#2 Bug fixes

Bug fixes:

• Disable temp buttons on press, show spinner, reenable after 5s if no response
• Only show silvia indicator if Machine 1/0 button on (by looking at PID messages)
• Show spinner when not connected
• Show toaster when shot timer starts, cancel runnable if user restarts shot timer.

fixes #1

Changes in activity_main.xml are mainly formatting from my IDE