Add strings for reset speech pitch button in Text-to-Speech output

    <!-- [CHAR LIMIT=50] Title of the settings section that displays general preferences

         that are applicable to all engines, such as the speech rate -->

    <string name="tts_general_section_title">General</string>

    <!-- On main TTS Settings screen, in default settings section,

         reset speech pitch of synthesized voice to 1x speech pitch. [CHAR LIMIT=50] -->

    <string name="tts_reset_speech_pitch_title">Reset speech pitch</string>

    <!--On main TTS Settings screen, summary for reset speech pitch of synthesized voice [CHAR LIMIT=150] -->

    <string name="tts_reset_speech_pitch_summary">Reset the pitch at which the text is spoken to default.</string>

    <!-- Default speech rate choices -->

    <string-array name="tts_rate_entries">