Remove StorageManager#isUserKeyUnlocked()

StorageManager#isUserKeyUnlocked() is no longer used, since all callers
have switched to using StorageManager#isCeStorageUnlocked() which has a
clearer name.  Therefore, remove StorageManager#isUserKeyUnlocked().

Note that isUserKeyUnlocked() is a @TestApi and isCeStorageUnlocked()
isn't.  This is fine because no CTS tests call either method, so
@TestApi is unnecessary.  And unlike regular APIs, Test APIs may be
added/changed/removed at any time.  Of course, we can always add
@TestApi to isCeStorageUnlocked() later if it actually becomes needed.

Bug: 306204742
Test: build
Change-Id: Ibf7dcccf85bdc566941d6c401ca8ad3d19fd6fc1
diff --git a/core/api/test-current.txt b/core/api/test-current.txt
index d01706d..d189a59 100644
--- a/core/api/test-current.txt
+++ b/core/api/test-current.txt
@@ -2582,7 +2582,6 @@
     method @NonNull public static String convert(@NonNull java.util.UUID);
     method @Nullable public String getCloudMediaProvider();
     method public boolean isAppIoBlocked(@NonNull java.util.UUID, int, int, int);
-    method public static boolean isUserKeyUnlocked(int);
     field public static final String CACHE_RESERVE_PERCENT_HIGH_KEY = "cache_reserve_percent_high";
     field public static final String CACHE_RESERVE_PERCENT_LOW_KEY = "cache_reserve_percent_low";
     field public static final String STORAGE_THRESHOLD_PERCENT_HIGH_KEY = "storage_threshold_percent_high";
diff --git a/core/java/android/os/storage/StorageManager.java b/core/java/android/os/storage/StorageManager.java
index eb1db3e..4c3f330 100644
--- a/core/java/android/os/storage/StorageManager.java
+++ b/core/java/android/os/storage/StorageManager.java
@@ -1669,12 +1669,6 @@
         }
     }
 
-    /** {@hide} */
-    @TestApi
-    public static boolean isUserKeyUnlocked(int userId) {
-        return isCeStorageUnlocked(userId);
-    }
-
     /**
      * Returns true if the user's credential-encrypted (CE) storage is unlocked.
      *