Update WcdmaSignalStrength to add RAT-specific fields

-Add RSCP and ECNO to WcdmaSignalStrength
-Add WcdmaSignalStrength to SignalStrength struct.

With this change we can now report the correct WCDMA
ASU due to our ability to now differentiate the SS
based on the RAT without needing additional info.

Bug: 71329173
Test: runtest frameworks-telephony
Change-Id: Ibce0ba38bf2d7e4f3e6c09f53303c0ba83dc6080