Telephony: Fix NPE while opening allowed number.

Trying to edit existing allowed number caused NPE:

mNameField and mNumberField setText caused TextWatcher afterTextChanged
event while mButton is still null. So set mButton before setTexts.

Change-Id: If444e2d69c77bc10094a1dfd3fc6b700509c6128
TeleService: For Msim DSDS, set mode to 2g(all sims) prior to change

* DSDS have a wierd behavior that all sims need to be toggle to 2g before switching
to 3g or above.

Change-Id: Iccd409ea0811a2a041d0e707da6285ed5d3375cd
Telephony: bugfix - let us edit 'My phone number' again

http://review.cyanogenmod.org/#/c/75688/3 introduced a change on "My Phone
Number", having the option disabled at the beginning, so it can only be used
after it has been init'd.
This commit now enables the option, when init is done.

Change-Id: I50438ac5231934b9c28d7161c05438ab4519aa8b
TeleService: Refactor sim name / sim label logic

Change-Id: I63a0a2f4d03b91289354cd9d6b51495cd622f760