CSIS: Don't use cached RSI value

Using cached RSI value can speed up the service discovery process, but
it causing some issues.
Assumption in this code was that scan is performed from Settings, and
each time scan is started, we clean the cache, tBTM_INQ_INFO.
However, if app starts LE only scan (i.e. FastPair), we don't know how
old the result is, and can attempt to connect to devices that are long
gone.
For now, disable the use of RSI cache.

Test: Pair with FP capable devices multiple times in a row in span of
couple minutes, ensure both devices are paired each time
Bug: 285191013

Change-Id: Ia61acb37e8920527acd6d1b07e9c6fd7e84a0683