Moving the error messages from slice to panel's subtitle

Bug: 180888831
Test: atest ProviderModelSliceTest
atest ProviderModelSliceHelperTest
atest NetworkProviderWorkerTest
atest InternetConnectivityPanelTest
make RunSettingsRoboTests -j

Change-Id: I4572c8ad15effab0c95feaeac6a99f5aaabf6f90
6 files changed