Check more errors for VTS getSlicingConfig

- add RADIO_NOT_AVAILABLE/INTERNAL_ERR/MODEM_ERR errors for
  normal case as defined in IRadioResponse.hal

Bug: 181634613
Test: *
run command => atest VtsHalRadioV1_6TargetTest -- --test-arg com.android.tradefed.testtype.GTest:native-test-flag:"--gtest_filter=*slot1"
and check the test result is PASSED
[3/19] PerInstance/RadioHidlTest_v1_6#getSlicingConfig/0_slot1: PASSED (28ms)

Change-Id: If813cc51d0d06138aeebe4b528569c214677a1d2