PEEK 2/2

AICP:
Modified for AICP source
Added toast warning on settings enable

PS3,4: No change
PS5: Commit message updated

Change-Id: I2498c536048c7a809d6ff70b293fcea7c4cd7fda
Settings: check if NfcAdapter is null

Change-Id: Ib71762b5a5326ade5cab3bebb9b880bdeb7da178
Merge changes Ib71762b5,I2498c536 into kitkat

* changes:
  Settings: check if NfcAdapter is null
  PEEK 2/2