Make Beam more forgiving.

- Increased debounce time when nobody has pressed send
  yet to 3 seconds - this gives users significantly
  more time to press send, even when the link is down.
  The only downside is that we stick in the Beam-animation
  a bit longer, but in 99% of cases users actually intent
  to send something, so this should be no problem.
- When the user does touch to send, if the link is down,
  an even more forgiving debounce timer is started -
  given the user 5 seconds to get the devices back
  together. When they do get back together, the send
  completes automatically.
- Also show a UI hint to get the devices back together whenever
  the user has touched to send, but the link is broken.

Bug: 7124631
Change-Id: I0b0260f4eb92b11bf6bea8e571b43b38759c2bcc
5 files changed