Bug 998488 - STK PLAY_TONE feature broken r=fcampo

- Access _iccManager from icc instead of iccManager

- Add test case for PLAY_TONE

Change-Id: I701dec50e81fd25357552e33e2a00e4abd28b35d
Merge pull request #18463 from nsarkar/bug998488

Bug 998488 - STK PLAY_TONE feature broken r=etienne