make public API to get Passpoint unique ID

This is needed by Settings and SUW to distinguish passpoint networks
sharing the same FQDN.

Bug: 269045781
Test: build, CTS
Change-Id: I225cf2edf7ef8d0b790536a4fb7e29d73ab0945e
diff --git a/framework/api/current.txt b/framework/api/current.txt
index 9b303d1..bd72682 100644
--- a/framework/api/current.txt
+++ b/framework/api/current.txt
@@ -390,6 +390,7 @@
     method public int getNetworkId();
     method @Nullable public String getPasspointFqdn();
     method @Nullable public String getPasspointProviderFriendlyName();
+    method @FlaggedApi("com.android.wifi.flags.android_v_wifi_api") @Nullable public String getPasspointUniqueId();
     method public int getRssi();
     method @IntRange(from=0xffffffff) public int getRxLinkSpeedMbps();
     method public String getSSID();