Create Central Version of dataStateToString()

There are currently two slightly-different copies of
dataStateToString().
-TelephonyManager#dataStateToString()
-TelephonyRegistry#dataStateToString()

The TelephonyRegistry version doesn't have a string for the
DISCONNECTING state. In order to have a single copy that can
be accessed from TelephonyRegistry (not mainline) and TelephonyManager
(mainline), move both copies to TelephonyUtils.

Bug: 149717408
Test: make; atest TelephonyRegistryTest
Change-Id: I36945a8a432f7b4f0c449f7414996372e852b5b8

services/core/java/com/android/server/TelephonyRegistry.java

@@ -85,6 +85,7 @@ import com.android.internal.telephony.IOnSubscriptionsChangedListener;
 import com.android.internal.telephony.IPhoneStateListener;
 import com.android.internal.telephony.ITelephonyRegistry;
 import com.android.internal.telephony.TelephonyPermissions;
+import com.android.internal.telephony.util.TelephonyUtils;
 import com.android.internal.util.ArrayUtils;
 import com.android.internal.util.DumpUtils;
 import com.android.internal.util.FrameworkStatsLog;
@@ -1657,7 +1658,7 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
                         && (mDataConnectionState[phoneId] != state
                         || mDataConnectionNetworkType[phoneId] != networkType)) {
                     String str = "onDataConnectionStateChanged("
-                            + dataStateToString(state)
+                            + TelephonyUtils.dataStateToString(state)
                             + ", " + getNetworkTypeName(networkType)
                             + ") subId=" + subId + ", phoneId=" + phoneId;
                     log(str);
@@ -2518,7 +2519,7 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
         // status bar takes care of that after taking into account all of the
         // required info.
         Intent intent = new Intent(ACTION_ANY_DATA_CONNECTION_STATE_CHANGED);
-        intent.putExtra(PHONE_CONSTANTS_STATE_KEY, dataStateToString(state));
+        intent.putExtra(PHONE_CONSTANTS_STATE_KEY, TelephonyUtils.dataStateToString(state));
         intent.putExtra(PHONE_CONSTANTS_DATA_APN_KEY, apn);
         intent.putExtra(PHONE_CONSTANTS_DATA_APN_TYPE_KEY,
                 ApnSetting.getApnTypesStringFromBitmask(apnType));
@@ -2857,21 +2858,6 @@ public class TelephonyRegistry extends ITelephonyRegistry.Stub {
         }
     }
 
-    /**
-     * Convert TelephonyManager.DATA_* to string.
-     *
-     * @return The data state in string format.
-     */
-    private static String dataStateToString(int state) {
-        switch (state) {
-            case TelephonyManager.DATA_DISCONNECTED: return "DISCONNECTED";
-            case TelephonyManager.DATA_CONNECTING: return "CONNECTING";
-            case TelephonyManager.DATA_CONNECTED: return "CONNECTED";
-            case TelephonyManager.DATA_SUSPENDED: return "SUSPENDED";
-        }
-        return "UNKNOWN(" + state + ")";
-    }
-
     /**
      * Returns a string representation of the radio technology (network type)
      * currently in use on the device.

telephony/common/com/android/internal/telephony/util/TelephonyUtils.java

@@ -15,6 +15,8 @@
  */
 package com.android.internal.telephony.util;
 
+import static android.telephony.Annotation.DataState;
+
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.content.Context;
@@ -26,6 +28,7 @@ import android.os.Bundle;
 import android.os.PersistableBundle;
 import android.os.RemoteException;
 import android.os.SystemProperties;
+import android.telephony.TelephonyManager;
 
 import java.io.PrintWriter;
 import java.util.Collections;
@@ -154,4 +157,22 @@ public final class TelephonyUtils {
         } catch (InterruptedException ignored) {
         }
     }
+
+    /**
+     * Convert data state to string
+     *
+     * @return The data state in string format.
+     */
+    public static String dataStateToString(@DataState int state) {
+        switch (state) {
+            case TelephonyManager.DATA_DISCONNECTED: return "DISCONNECTED";
+            case TelephonyManager.DATA_CONNECTING: return "CONNECTING";
+            case TelephonyManager.DATA_CONNECTED: return "CONNECTED";
+            case TelephonyManager.DATA_SUSPENDED: return "SUSPENDED";
+            case TelephonyManager.DATA_DISCONNECTING: return "DISCONNECTING";
+            case TelephonyManager.DATA_UNKNOWN: return "UNKNOWN";
+        }
+        // This is the error case. The well-defined value for UNKNOWN is -1.
+        return "UNKNOWN(" + state + ")";
+    }
 }

telephony/java/android/telephony/TelephonyManager.java

@@ -5594,23 +5594,6 @@ public class TelephonyManager {
         }
     }
 
-    /**
-     * Convert data state to string
-     *
-     * @return The data state in string format.
-     * @hide
-     */
-    public static String dataStateToString(@DataState int state) {
-        switch (state) {
-            case DATA_DISCONNECTED: return "DISCONNECTED";
-            case DATA_CONNECTING: return "CONNECTING";
-            case DATA_CONNECTED: return "CONNECTED";
-            case DATA_SUSPENDED: return "SUSPENDED";
-            case DATA_DISCONNECTING: return "DISCONNECTING";
-        }
-        return "UNKNOWN(" + state + ")";
-    }
-
    /**
     * @hide
     */