Fix AttributionSource#getDeviceId docs

Fix: 294292056
Test: presubmit
Change-Id: I6ebc5a59f5265f536cfa6b56884f98ff22044a6d
diff --git a/core/java/android/content/AttributionSource.java b/core/java/android/content/AttributionSource.java
index d0bb2b9..8f35ca2 100644
--- a/core/java/android/content/AttributionSource.java
+++ b/core/java/android/content/AttributionSource.java
@@ -517,7 +517,11 @@
     }
 
     /**
-     * The device ID for which permissions are checked.
+     * Gets the device ID for this attribution source. Attribution source can set the device ID
+     * using {@link Builder#setDeviceId(int)}, the default device ID is
+     * {@link Context#DEVICE_ID_DEFAULT}.
+     * <p>
+     * This device ID is used for permissions checking during attribution source validation.
      */
     public int getDeviceId() {
         return mAttributionSourceState.deviceId;