Remove setButtonPositive method

Since new UI design only exist two button in layout,
we don't need these methods anymore.

Test: robotest
Bug: 116346008
Change-Id: If2e8f7dddb9c13e480438f36fe3c5d6affa4e9ff

src/com/android/settings/tts/TextToSpeechSettings.java

@@ -171,11 +171,9 @@ public class TextToSpeechSettings extends SettingsPreferenceFragment
 
         mActionButtons = ((ActionButtonPreference) findPreference(KEY_ACTION_BUTTONS))
                 .setButton1Text(R.string.tts_play)
-                .setButton1Positive(true)
                 .setButton1OnClickListener(v -> speakSampleText())
                 .setButton1Enabled(false)
                 .setButton2Text(R.string.tts_reset)
-                .setButton2Positive(false)
                 .setButton2OnClickListener(v -> resetTts())
                 .setButton1Enabled(true);