Add a constructor for SecretStorageDefaultKeyEventContent

crates/ruma-events/src/secret_storage/default_key.rs

@@ -15,3 +15,13 @@ pub struct SecretStorageDefaultKeyEventContent {
     #[serde(rename = "key")]
     pub key_id: String,
 }
+
+impl SecretStorageDefaultKeyEventContent {
+    /// Create a new [`SecretStorageDefaultKeyEventContent`] with the given key ID.
+    ///
+    /// Uploading this to the account data will mark the secret storage key with the given key ID as
+    /// the default key.
+    pub fn new(key_id: String) -> Self {
+        Self { key_id }
+    }
+}