fix WRITE_SETTINGS to be "dangerous"

(see http://www.fireeye.com/blog/technical/2014/04/occupy_your_icons_silently_on_android.html for an explanation why this is dangerous)

Change-Id: I8f938dc4f528aa2ccbca3d4cec235feb0299c0bd
TelephonyManager: isSmsCapable: respect telephony properties

The 2 telephony properties override if SMS send/receive is enabled
in the telephony code. Also respect them for the isSmsCapable API.

Use case: Acer A700/701 (Wi-Fi only/3G) share the same build

Change-Id: Iaa1b45c62fa5a48a4c4a222d5e47980dd1678d48
Merge changes Iaa1b45c6,I8f938dc4 into android-4.4

* changes:
  TelephonyManager: isSmsCapable: respect telephony properties
  fix WRITE_SETTINGS to be "dangerous"