Consolidate group expansion handling

There is a small behavior change - if you double expand a minimized group,
when collapsing the group it'll return to its initial stage, rather than
the 'expanded once' state.
was: min -> normal collapsed appearance -> fully expanded -> normal collapsed
now: min -> normal collapsed appearance -> fully expanded -> min

Test: ExpandableNotificationRowTest
Manual: expand group, long press, launch settings intent, open shade - group is collapsed
Manual: post group in 1 & 2 positions in shade - view lock screen - groups are collapsed
Manual: expand group, collapse and expand shade - group is collapsed
Flag: EXEMPT bug fix
Fixes: 438722024
Change-Id: I8a799676160c8665d251b50ac7a1acce1eb3a1ca