[Thread] add documentation for Pending Dataset constructor

Per API council review feedback in b/307939803

Bug: 307939803
Test: atest CtsThreadNetworkTestCases
Change-Id: Ia5fbb38e24d09c4a8d95ce0dfd6058a65d5d4614
diff --git a/thread/framework/java/android/net/thread/PendingOperationalDataset.java b/thread/framework/java/android/net/thread/PendingOperationalDataset.java
index 4762d7f..9cfd0b8 100644
--- a/thread/framework/java/android/net/thread/PendingOperationalDataset.java
+++ b/thread/framework/java/android/net/thread/PendingOperationalDataset.java
@@ -69,7 +69,15 @@
     @NonNull private final OperationalDatasetTimestamp mPendingTimestamp;
     @NonNull private final Duration mDelayTimer;
 
-    /** Creates a new {@link PendingOperationalDataset} object. */
+    /**
+     * Creates a new {@link PendingOperationalDataset} object.
+     *
+     * @param activeOpDataset the included Active Operational Dataset
+     * @param pendingTimestamp the Pending Timestamp which represents the version of this Pending
+     *     Dataset
+     * @param delayTimer the delay after when {@code activeOpDataset} will be committed on this
+     *     device
+     */
     public PendingOperationalDataset(
             @NonNull ActiveOperationalDataset activeOpDataset,
             @NonNull OperationalDatasetTimestamp pendingTimestamp,