Re-enable SyncService.withEncryptionSync to improve decryption of notifications (#1199)

* Re-enable `SyncService.withEncryptionSync` to improve decryption of notifications.

* Add feature flag

samples/minimal/build.gradle.kts

@@ -63,6 +63,7 @@ dependencies {
     implementation(projects.features.login.impl)
     implementation(projects.features.networkmonitor.impl)
     implementation(projects.services.toolbox.impl)
+    implementation(projects.libraries.featureflag.impl)
     implementation(libs.coroutines.core)
     coreLibraryDesugaring(libs.android.desugar)
 }

samples/minimal/src/main/kotlin/io/element/android/samples/minimal/MainActivity.kt

@@ -26,6 +26,7 @@ import androidx.compose.runtime.getValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.core.view.WindowCompat
+import io.element.android.libraries.featureflag.impl.DefaultFeatureFlagService
 import io.element.android.libraries.matrix.api.auth.MatrixAuthenticationService
 import io.element.android.libraries.matrix.impl.RustMatrixClientFactory
 import io.element.android.libraries.matrix.impl.auth.RustMatrixAuthenticationService
@@ -54,7 +55,8 @@ class MainActivity : ComponentActivity() {
                 coroutineDispatchers = Singleton.coroutineDispatchers,
                 sessionStore = sessionStore,
                 userAgentProvider = userAgentProvider,
-                clock = DefaultSystemClock()
+                clock = DefaultSystemClock(),
+                featureFlagsService = DefaultFeatureFlagService(emptySet())
             )
         )
     }