sound: Remove set_theme_id() from id initialization

sound: Remove set_theme_id() from id initialization

When the sound current_theme_id is initialized,
there is no need to call sound_set_theme_id().
Because sound_set_theme_id() calls vconf_set_int(),
this requires privilege "http://tizen.org/privilege/systemsettings.admin" when it call for
VCONFKEY_SETAPPL_ACCESSIBILITY_SOUND_FEEDBACK_THEME.
That makes all apps have that privilege during sound init process.
Thus, this function usage is removed.

Current theme id policy is as follows.

1. If there is a set vconf value, current theme id follows that value.
2. It there is no set vconf value, current theme id will be default theme id by sound conf parsing.

Change-Id: Ie526151a993006793902bb502f915d8b94c996b3
Signed-off-by: Yunhee Seo <yuni.seo@samsung.com>