Improve the comments of getMedium.

Also remove public identity type as it's not used.

Bug:222291470

Test: atest CtsNearbyFastPairTestCases
Ignore-AOSP-First: new project
Change-Id: I938fbabc4c042da91b1d316b0bf892cb377db1ba
diff --git a/framework-t/api/system-current.txt b/framework-t/api/system-current.txt
index 03f9c8e..4f41cc7 100644
--- a/framework-t/api/system-current.txt
+++ b/framework-t/api/system-current.txt
@@ -26,6 +26,7 @@
     method public int getVersion();
     field public static final int BROADCAST_TYPE_NEARBY_PRESENCE = 3; // 0x3
     field public static final int BROADCAST_TYPE_UNKNOWN = -1; // 0xffffffff
+    field public static final int MEDIUM_BLE = 1; // 0x1
     field public static final int PRESENCE_VERSION_UNKNOWN = -1; // 0xffffffff
     field public static final int PRESENCE_VERSION_V0 = 0; // 0x0
     field public static final int PRESENCE_VERSION_V1 = 1; // 0x1
@@ -338,7 +339,6 @@
     field public static final int CREDENTIAL_TYPE_PUBLIC = 1; // 0x1
     field public static final int IDENTITY_TYPE_PRIVATE = 1; // 0x1
     field public static final int IDENTITY_TYPE_PROVISIONED = 2; // 0x2
-    field public static final int IDENTITY_TYPE_PUBLIC = 4; // 0x4
     field public static final int IDENTITY_TYPE_TRUSTED = 3; // 0x3
     field public static final int IDENTITY_TYPE_UNKNOWN = 0; // 0x0
   }