adding documentation to the new session listener

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/NewSessionListener.kt

@@ -15,6 +15,15 @@
  */
 package org.matrix.android.sdk.internal.crypto
 
+/**
+ * This listener notifies on new Megolm sessions being created
+ */
 interface NewSessionListener {
+
+    /**
+     * @param roomId the room id where the new Megolm session has been created for, may be null when importing from external sessions
+     * @param senderKey the sender key of the device which the Megolm session is shared with
+     * @param sessionId the session id of the Megolm session
+     */
     fun onNewSession(roomId: String?, senderKey: String, sessionId: String)
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/algorithms/megolm/MXMegolmDecryption.kt

@@ -325,6 +325,7 @@ internal class MXMegolmDecryption(private val userId: String,
     /**
      * Check if the some messages can be decrypted with a new session
      *
+     * @param roomId the room id where the new Megolm session has been created for, may be null when importing from external sessions
      * @param senderKey the session sender key
      * @param sessionId the session id
      */