make the password-clearing algorithm smarter

Remove the ro.config.sim_password_clear property; go back to enabling
this for all devices.  For GSM devices, we clear the password on SIM
change as before.  For CDMA devices, we only clear when the device is
provisioned with a different number; we don't clear the password while
the device is unprovisioned.
diff --git a/core/java/android/accounts/AccountManagerService.java b/core/java/android/accounts/AccountManagerService.java
index be74073..8af5fa4 100644
--- a/core/java/android/accounts/AccountManagerService.java
+++ b/core/java/android/accounts/AccountManagerService.java
@@ -16,22 +16,27 @@
 
 package android.accounts;
 
+import android.Manifest;
+import android.app.Notification;
+import android.app.NotificationManager;
+import android.app.PendingIntent;
 import android.content.BroadcastReceiver;
+import android.content.ComponentName;
 import android.content.ContentValues;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.ServiceConnection;
-import android.content.ComponentName;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.RegisteredServicesCache;
-import android.content.pm.PackageInfo;
-import android.content.pm.ApplicationInfo;
 import android.content.pm.RegisteredServicesCacheListener;
 import android.database.Cursor;
 import android.database.DatabaseUtils;
 import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteOpenHelper;
+import android.os.Binder;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.HandlerThread;
@@ -39,17 +44,13 @@
 import android.os.Looper;
 import android.os.Message;
 import android.os.RemoteException;
+import android.os.ServiceManager;
 import android.os.SystemClock;
-import android.os.Binder;
 import android.os.SystemProperties;
 import android.telephony.TelephonyManager;
 import android.text.TextUtils;
 import android.util.Log;
 import android.util.Pair;
-import android.app.PendingIntent;
-import android.app.NotificationManager;
-import android.app.Notification;
-import android.Manifest;
 
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
@@ -60,8 +61,9 @@
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
 
-import com.android.internal.telephony.TelephonyIntents;
 import com.android.internal.R;
+import com.android.internal.telephony.ITelephony;
+import com.android.internal.telephony.TelephonyIntents;
 
 /**
  * A system service that provides  account, password, and authtoken management for all
@@ -220,11 +222,7 @@
         mAuthenticatorCache = new AccountAuthenticatorCache(mContext);
         mAuthenticatorCache.setListener(this);
 
-        if (SystemProperties.getBoolean("ro.config.sim_password_clear", false)) {
-          mSimWatcher = new SimWatcher(mContext);
-        } else {
-          mSimWatcher = null;
-        }
+        mSimWatcher = new SimWatcher(mContext);
         sThis.set(this);
 
         onRegisteredServicesCacheChanged();
@@ -1443,16 +1441,58 @@
          */
         @Override
         public void onReceive(Context context, Intent intent) {
-            // Check IMSI on every update; nothing happens if the IMSI is missing or unchanged.
-            String imsi = ((TelephonyManager) context.getSystemService(
-                    Context.TELEPHONY_SERVICE)).getSubscriberId();
+            // Check IMSI on every update; nothing happens if the IMSI
+            // is missing or unchanged.
+            TelephonyManager telephonyManager =
+                (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
+            if (telephonyManager == null) {
+                Log.w(TAG, "failed to get TelephonyManager");
+                return;
+            }
+            String imsi = telephonyManager.getSubscriberId();
+
+            // If the subscriber ID is an empty string, don't do anything.
             if (TextUtils.isEmpty(imsi)) return;
 
+            // If the current IMSI matches what's stored, don't do anything.
             String storedImsi = getMetaValue("imsi");
-
             if (Log.isLoggable(TAG, Log.VERBOSE)) {
                 Log.v(TAG, "current IMSI=" + imsi + "; stored IMSI=" + storedImsi);
             }
+            if (imsi.equals(storedImsi)) return;
+
+            // If a CDMA phone is unprovisioned, getSubscriberId()
+            // will return a different value, but we *don't* erase the
+            // passwords.  We only erase them if it has a different
+            // subscriber ID once it's provisioned.
+            if (telephonyManager.getPhoneType() == TelephonyManager.PHONE_TYPE_CDMA) {
+                IBinder service = ServiceManager.checkService(Context.TELEPHONY_SERVICE);
+                if (service == null) {
+                    Log.w(TAG, "call to checkService(TELEPHONY_SERVICE) failed");
+                    return;
+                }
+                ITelephony telephony = ITelephony.Stub.asInterface(service);
+                if (telephony == null) {
+                    Log.w(TAG, "failed to get ITelephony interface");
+                    return;
+                }
+                boolean needsProvisioning;
+                try {
+                    needsProvisioning = telephony.getCdmaNeedsProvisioning();
+                } catch (RemoteException e) {
+                    Log.w(TAG, "exception while checking provisioning", e);
+                    // default to NOT wiping out the passwords
+                    needsProvisioning = true;
+                }
+                if (needsProvisioning) {
+                    // if the phone needs re-provisioning, don't do anything.
+                    if (Log.isLoggable(TAG, Log.VERBOSE)) {
+                        Log.v(TAG, "current IMSI=" + imsi + " (needs provisioning); stored IMSI=" +
+                              storedImsi);
+                    }
+                    return;
+                }
+            }
 
             if (!imsi.equals(storedImsi) && !TextUtils.isEmpty(storedImsi)) {
                 Log.w(TAG, "wiping all passwords and authtokens because IMSI changed ("