Confusingly, specifying a null Locale object to the constructor
of SuggestionSpan does not necessarily mean that
SuggestionSpan#getLocale() returns null. The constructor in
question also receives Context object, and Context's locale can
be used as a fallback locale to initialize locale of
SuggestionSpan.
With this CL, LatinIME always specify non-null Locale object
when instantiating SuggestionSpan object. It basically
corresponds to the active main dictionary, but can be
Locale#ROOT when one locale is not determined for some reasons.
BUG: 20435013
Change-Id: I2c152466410327300e7dba4d7ed9a22f57c17c4f
490fa47a46