Use SharedPreferences.Editor#apply instead of commit

apply() is asynchronous while commit synchronously writes to disk.
Prevent lint from complaining that API level is inadequate
Remove final from private method
Remove useless intermediate variable
Remove ignored exception parameters
TextToSpeech#speak has been deprecated in API 21
Unnecessary unboxing
Remove a useless condition

At this point, guid cannot be null at the same time of the geocode, or
we would have returned early already.
Replace known value by constant
Style fixes
Remove useless null checks
Inline concatenation in string format parameter