One class, AlternativeSpan, represents a list of alternative hypotheses
for a specific span of the recognized string. It's using only builtin
types (two ints for the range and a List<String> for the hypotheses) and
is Parcelable.
The other class, AlternativeSpans, represents a list of objects of the
first class for a single speech recognition result. It is also
Parcelable. An ArrayList<AlternativeSpans> will be added to the
SpeechRecognizer result bundle under key RESULTS_ALTERNATIVES.
Classes' public API methods are tested in the corresponding CTS.
Bug: 231575601
Test: CTS
Change-Id: If6e0c4e803b8fee39ac12a2568ac738dcc9e0564
0fd5934060