Fix an action bar accessibility regression

A previous fix introduced a problem with building content descriptions
for accessibility of the home/up button in one code path while setting
display options flags. Correct the issue and also refresh content
descriptions immediately when setting related attributes one at a
time.

Bug 11542264

Change-Id: I40d07036d1026e8e40c77c47ac377c82edd827b4
1 file changed