UserDataPreparer: downgrade an error message from wtf

UserDataPreparerTest#testPrepareUserData_forNewUser_destroysOnFailure
and
UserDataPreparerTest#testPrepareUserData_forExistingUser_doesNotDestroyOnFailure
fail on eng builds because they exercise a code path in UserDataPreparer
that uses Log.wtf, and on eng builds Log.wtf causes the process to
abort.  Fix this by changing the message to ERROR level instead.

Bug: 316035110
Test: atest UserDataPreparerTest
Change-Id: I4dce4db37bf650b7f97e46638c03a429a135a3b6
diff --git a/services/core/java/com/android/server/pm/UserDataPreparer.java b/services/core/java/com/android/server/pm/UserDataPreparer.java
index 4c42c2d..1d41401 100644
--- a/services/core/java/com/android/server/pm/UserDataPreparer.java
+++ b/services/core/java/com/android/server/pm/UserDataPreparer.java
@@ -141,7 +141,7 @@
                 // If internal storage of the system user fails to prepare on first boot, then
                 // things are *really* broken, so we might as well reboot to recovery right away.
                 try {
-                    Log.wtf(TAG, "prepareUserData failed for user " + userId, e);
+                    Log.e(TAG, "prepareUserData failed for user " + userId, e);
                     if (isNewUser && userId == UserHandle.USER_SYSTEM && volumeUuid == null) {
                         RecoverySystem.rebootPromptAndWipeUserData(mContext,
                                 "failed to prepare internal storage for system user");