AutoSize TextView (part 9) - sanitize APIs naming

This CL is no-op (cosmetics only)
* renames autoSizeText type "xy" to "uniform"
* renames attribute "autoSizeStepSizeSet" to "autoSizePresetSizes"
* renames "AUTO_SIZE_TEXT_TYPE_XY" to "AUTO_SIZE_TEXT_TYPE_UNIFORM"
* renames public TextView#getAutoSizeTextPresetSizes() to public
  TextView#getAutoSizeTextAvailableSizes() because this method can
  return either preset sizes or computed sizes (via min/max/step)

Bug: 34923754
Bug: 32221168
Test: associated test renames in the same topic
Change-Id: Ifacccf21ca014b6c0a07322fa02b7859ee53e387