Use master branch for picotts

  <project path="prebuilts/prebuiltapks" name="e/os/android_prebuilts_prebuiltapks_lfs" remote="e" revision="main" />

  <!-- PicoTTS -->

  <project path="external/svox" name="e/os/picotts" remote="e" />

  <project path="external/svox" name="e/os/picotts" remote="e" revision="master" />

  <!-- vendor /e/os -->

  <project path="vendor/eos" name="e/os/android_vendor_eos" remote="e" />