change (media preview config) : use the new apis

libraries/preferences/impl/src/main/kotlin/io/element/android/libraries/preferences/impl/store/DefaultAppPreferencesStore.kt

@@ -85,24 +85,12 @@ class DefaultAppPreferencesStore @Inject constructor(
         }
     }
 
-    override suspend fun setHideInviteAvatars(value: Boolean) {
-        store.edit { prefs ->
-            prefs[hideInviteAvatarsKey] = value
-        }
-    }
-
     override fun getHideInviteAvatarsFlow(): Flow<Boolean> {
         return store.data.map { prefs ->
             prefs[hideInviteAvatarsKey] == true
         }
     }
 
-    override suspend fun setTimelineMediaPreviewValue(value: MediaPreviewValue) {
-        store.edit { prefs ->
-            prefs[timelineMediaPreviewValueKey] = value.name
-        }
-    }
-
     override fun getTimelineMediaPreviewValueFlow(): Flow<MediaPreviewValue> {
         return store.data.map { prefs ->
             prefs[timelineMediaPreviewValueKey]?.let { MediaPreviewValue.valueOf(it) } ?: MediaPreviewValue.On