Fix for empty "Listen to an example" string.

Because of bug in previous TTS related change (bugfix for hiding
"Play TTS sample" if default language is not supported), settings
stopped to call getSampleText() when it was established that current
default language is supported.

This change makes sure that getSampleText() is always called if language
is supported.

Bug: 10672535
Change-Id: I83bf7056e12ddbe2322b6a3f04552802037626aa