am bd2973db: am bbed0d68: hide setGammaForText, which is only used for calibrating new devices

Merge commit 'bd2973db0b0c2354b2ca793beed5048e66fbd023'

* commit 'bd2973db0b0c2354b2ca793beed5048e66fbd023':
  hide setGammaForText, which is only used for calibrating new devices