Telephony(MSIM): Disable DDS Switch in Airplane Mode.

Do not allow user to change the DDS in Airplane Mode
as modem will be in LPM state.

Change-Id: I21ceaa53df6f0acd7be5fb8f23a120f92023a152
CRs-Fixed: 594616
Settings: correct y-axis brightness in preview

To answer the comment in the code, no, the min brightness should not
correspond 0, but rather to the device min supported level. The values
on the preview graph should correspond exactly to the percent values
entered in the brightness configuration dialog.

Change-Id: I4a6d19b261f33f53d24437cde99e63e03ba3fc28