When there is no TTS engine selected, mTts.getVoice() will throw
a NullPointerException. This is a workaround to cope with this bug
in Android.

This reverts commit 6ac54860a1.

This change was preventing the voice data from being installed.

The Android 5.0 Text-to-speech output settings dialog checks that
the languages from CheckVoiceData use the ISO3 language and
country codes. This change matches that expectation.

This improves the performance of looking up a voice by name.

As of Android 5.0, TextToSpeech.setLanguage calls the new
TextToSpeechService.onGetDefaultVoiceNameFor(lang,country,variant)
and uses the specified voice name.

The default Android 5.0 implementation of onGetDefaultVoiceNameFor
does not work with eSpeak. This provides a working implementation.

This fixes the TextToSpeechTest.testLanguages tests on Android 5.0.

The default Android 5.0 implementation enumerates the available
locales. This enumerates the voices returned by eSpeak.

This changes the getLanguage helper to return the result from
getLanguage on all platform versions, disabling the deprecated
message on API 21 and above.

This adds method declarations for the new voice APIs, forwarding
them to the default implementations.

This creates a custom hamcrest matcher that maps the TextToSpeech
LANG_* constants to strings. This makes it easier to read the
text output when the tests fail.

The ART runtime is stricter about calling env->DeleteWeakGlobalRef
on an object/value that was not returned from env->NewWeakGlobalRef.
In that case, it triggers an abort which causes the application to
crash and display an "Application has stopped" dialog message.