Ensure sim color is shown on multi-sim devices when only one sim installed.

- Removed telecomManager check hasMultipleCallCapableAccounts() which would
only return 1 when a single sim is installed in a multisim phone.
- For single-sim devices, the Sim color is 0 (ie not selected) for the
Sim PhoneAccount, so the default behavior is to not show a sim color.

Bug: 18696518
Change-Id: I8bbb956e204422e122b3c50e6fc98c2916151aa4