CMAccount: don't crash when toggling nav keys quickly

Same symptom appears in Settings. Avoid the race condition
by adding a slight delay.

Change-Id: Ifea43d3281dd49cd8f428d6e7c2bb0a229939186
Signed-off-by: Roman Birg <roman@cyngn.com>
Merge "CMAccount: don't crash when toggling nav keys quickly" into cm-11.0