SignalStrength: Hotfix TD-SCDMA

These checks need to be reviewed, they're making unwarranted assumptions
about signal value formats and possible tech combos.
This appears to work for all possible scenarios I was able to test,
but the "LTE checks" shouln't be necessary at all.

Change-Id: I659d4fc5cb9690634e802b62c7b55786ec137239