leaudio: Set TargetLatency for known configurations

All 48khz sink only configurations are set with TargetLatency = RELIABILITY
This set of configurations is presumed to be media context type

All same rate sink + src configurations are set with TargetLatency = LOW
This set of configurations is presumed to be conversation context type

Test: Manual (compiled and tested media/conversation cases on device)

Change-Id: I28c2c0b6843b0e26d4ebbb53a44d43cb604507ca