Make SeekBarPreference to be selectable

Fixes: 132983200
Test: make RunSettingsRoboTests, manual
Change-Id: I3d4bc59d948236ff2482945a4fc976ee61c37c27

src/com/android/settings/widget/SeekBarPreference.java

@@ -69,6 +69,13 @@ public class SeekBarPreference extends RestrictedPreference
                 com.android.internal.R.layout.preference_widget_seekbar);
         a.recycle();
 
+        a = context.obtainStyledAttributes(
+                attrs, com.android.internal.R.styleable.Preference, defStyleAttr, defStyleRes);
+        final boolean isSelectable = a.getBoolean(
+                com.android.settings.R.styleable.Preference_android_selectable, false);
+        setSelectable(isSelectable);
+        a.recycle();
+
         setLayoutResource(layoutResId);
     }
 
@@ -93,7 +100,11 @@ public class SeekBarPreference extends RestrictedPreference
 
     @Override
     public boolean isSelectable() {
-        return isDisabledByAdmin();
+        if(isDisabledByAdmin()) {
+            return true;
+        } else {
+            return super.isSelectable();
+        }
     }
 
     @Override