TelephonyProperties: Alpha ID fix for OPEN_CHANNEL and other p-commands (1/2)

p-cmds that support the below mentioned scenarios:
- SETUP CALL
- OPEN CHANNEL
- SEND DTMF
- SEND SMS
- SEND SS
- SEND USSD
- LAUNCH BROWSER
- PLAY TONE
- SELECT ITEM

Senarios handled :
- NO ALPHA ID : Introduce a new configurable sys prop
  "persist.atel.noalpha.usrcnf".
   --  Allow display of default UI confirmation if prop is set to true
   --  No UI confirmation to be show if prop is set to false
- NULL ALPHA ID (len = 0 ) :
   -- NO UI confirmation to be displayed

Change-Id: I79dfb4df1df51ba691a8326cbda48d64c83c0e9a