Keep 4G LTE slider disabled after call

We were not checking the carrier config after
a call ended and disabling the 4G LTE slider.
This was causing bugs where the user was able
to disable (but not enable) 4G LTE and get it
stuck in that state until reboot.

Bug: 64195239
Test: Manual
Change-Id: Ic4a9df5b195d26784638b77914874e5fc32736c1
1 file changed