Display message if Bluetooth is unavailable

[taquitos]

We don't present any errors if bluetooth isn't available, we probably should

https://github.com/google/science-journal-ios/blob/be7ecf0c3749793d6b18c1058d343a66c6d4314d/ScienceJournal/UI/SensorSettingsDataSource.swift#L446

[RadiBarq]

@taquitos hey, I am working on the issue should I present an alert only when the bluetooth is not available the first time the setting view open or every time the bluetooth is not available while the settings view is open, (for example if the user turned off the bluetooth while it's open).

[taquitos]

Great question, I think we could split this into two different PRs, and feel free to do either, or both!

1. I think every time somebody opens settings while bluetooth isn't available we should show an alert.
2. If bluetooth is turned off while it's open we should present an alert.

We have some standard alerting via MDCSnackbarMessage I think that would be the best way to alert the users.

[RadiBarq]

ok thank you, I will do both. About the warning message, do you translate texts to all the supported languages manually or what. and if there is a suggested warning message in english to be translated to other languages that's would be great.

[taquitos]

We do translation in-house- we write an English string and then a team takes care of the rest. Maybe something like: "Bluetooth is disabled, please enable to use external sensors." Paging @garrettmurray (he's much better at words than I 😄 )

[garrettmurray]

Let's match the Android string here: https://github.com/google/science-journal/blob/2521c303bc420d0c7fb141cc545771cbcd139579/OpenScienceJournal/whistlepunk_library/src/main/res/values/strings.xml#L778

Cannot connect to external sensor: Bluetooth is disabled. Turn on Bluetooth to connect to your external sensor.