Add new groups for LE hearing and hearable devices

Split current categories to LE and non-LE groups. This will double the
categories number to 8 for now. (New paired or not x LE audio or not x
hearing or hearable devices).

Flag: EXEMPT log only
Bug: 407477051
Test: atest HearingAidStatsLogUtilsTest
Change-Id: Ic1bbb76514ec6f584523ceab2b9159a17bd2173d