Start sync manually after completing the auth flow (#7734)

Do it before we wait for the known verification state so we can receive updates from the encryption sliding sync flow.

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/auth/RustMatrixAuthenticationService.kt

@@ -381,6 +381,9 @@ class RustMatrixAuthenticationService(
         // Apply enterprise hooks to the newly created client as soon as possible
         clientEnterpriseHook(matrixClient)
 
+        // Start the sync service to ensure that the client receives the encryption updates we'll wait for next.
+        matrixClient.syncService.startSync()
+
         matrixClient.waitForKnownVerificationState()
 
         newMatrixClientObservers.forEach { it.invoke(matrixClient) }