Add getter methods in SubInfoRecord for UI. Adapt PhoneAccount.

Settings and Dialer need label, icon, and color for UI display of
subscriptions/SIMs. Add getters for these methods in SubInfoRecord. Sets
up for the following changes:
+ getIcon will return a drawable instead of a resource ID
+ getColor will return a color value instead of an index
PhoneAccount will also be adding these changes which will be adopted
from SubInfoRecord. Adds changes that were reverted from ag/563976.

Bug: 17971273
Change-Id: Ie2beedf8475c6deb48a6ab83bc9656c1142cc004