Improve logs in pending result

[Diolor]

@jpribble now we can two cases:

• logger.log("Couldn't deliver pending result: Camera stopped before delivering result.")
• logger.log("Couldn't deliver pending result: Operation failed internally.")

In theory both can be ignored.

• First one means that camera stopped before it had the time the pending result to deliver the result.
• Second means internal camera issue. E.g. some devices don't return previews sizes (well in that case whole camera will not boot)

Still you see the 2nd it worth some investigation if we have bugs on our side

[Diolor]

Fixes #170