[Mainline] Create getDataRegistrationState and expose as system api

Bug: 144486008
Test: atest ServiceStateTest  (PASS)

Change-Id: Ice803f412135932ac2cedadc09433957c16ea512

api/system-current.txt

@@ -9485,6 +9485,7 @@ package android.telephony {
   }
 
   public class ServiceState implements android.os.Parcelable {
+    method public int getDataRegistrationState();
     method @Nullable public android.telephony.NetworkRegistrationInfo getNetworkRegistrationInfo(int, int);
     method @NonNull public java.util.List<android.telephony.NetworkRegistrationInfo> getNetworkRegistrationInfoList();
     method @NonNull public java.util.List<android.telephony.NetworkRegistrationInfo> getNetworkRegistrationInfoListForDomain(int);

telephony/java/android/telephony/ServiceState.java

@@ -65,6 +65,13 @@ public class ServiceState implements Parcelable {
     static final boolean DBG = false;
     static final boolean VDBG = false;  // STOPSHIP if true
 
+    /** @hide */
+    @Retention(RetentionPolicy.SOURCE)
+    @IntDef(prefix = "STATE_",
+            value = {STATE_IN_SERVICE, STATE_OUT_OF_SERVICE, STATE_EMERGENCY_ONLY,
+                    STATE_POWER_OFF})
+    public @interface RegState {}
+
     /**
      * Normal operation condition, the phone is registered
      * with an operator either in home network or in roaming.
@@ -83,6 +90,7 @@ public class ServiceState implements Parcelable {
     /**
      * The phone is registered and locked.  Only emergency numbers are allowed. {@more}
      */
+    //TODO: This state is not used anymore. It should be deprecated in a future release.
     public static final int STATE_EMERGENCY_ONLY =
             TelephonyProtoEnums.SERVICE_STATE_EMERGENCY_ONLY;  // 2
 
@@ -501,13 +509,15 @@ public class ServiceState implements Parcelable {
     }
 
     /**
-     * Get current data service state
+     * Get current data registration state.
      *
      * @see #STATE_IN_SERVICE
      * @see #STATE_OUT_OF_SERVICE
      * @see #STATE_EMERGENCY_ONLY
      * @see #STATE_POWER_OFF
      *
+     * @return current data registration state {@link RegState}
+     *
      * @hide
      */
     @UnsupportedAppUsage
@@ -515,6 +525,23 @@ public class ServiceState implements Parcelable {
         return mDataRegState;
     }
 
+    /**
+     * Get current data registration state.
+     *
+     * @see #STATE_IN_SERVICE
+     * @see #STATE_OUT_OF_SERVICE
+     * @see #STATE_EMERGENCY_ONLY
+     * @see #STATE_POWER_OFF
+     *
+     * @return current data registration state {@link RegState}
+     *
+     * @hide
+     */
+    @SystemApi
+    public @RegState int getDataRegistrationState() {
+        return getDataRegState();
+    }
+
     /**
      * Get the current duplex mode
      *
@@ -1408,7 +1435,15 @@ public class ServiceState implements Parcelable {
         return getRilDataRadioTechnology();
     }
 
-    /** @hide */
+    /**
+     * Transform RIL radio technology {@link RilRadioTechnology} value to Network
+     * type {@link NetworkType}.
+     *
+     * @param rat The RIL radio technology {@link RilRadioTechnology}.
+     * @return The network type {@link NetworkType}.
+     *
+     * @hide
+     */
     public static int rilRadioTechnologyToNetworkType(@RilRadioTechnology int rat) {
         switch(rat) {
             case RIL_RADIO_TECHNOLOGY_GPRS:
@@ -1490,7 +1525,15 @@ public class ServiceState implements Parcelable {
         }
     }
 
-    /** @hide */
+    /**
+     * Transform network type {@link NetworkType} value to RIL radio technology
+     * {@link RilRadioTechnology}.
+     *
+     * @param networkType The network type {@link NetworkType}.
+     * @return The RIL radio technology {@link RilRadioTechnology}.
+     *
+     * @hide
+     */
     public static int networkTypeToRilRadioTechnology(int networkType) {
         switch(networkType) {
             case TelephonyManager.NETWORK_TYPE_GPRS:
@@ -1691,7 +1734,14 @@ public class ServiceState implements Parcelable {
         return bearerBitmask;
     }
 
-    /** @hide */
+    /**
+     * Convert network type bitmask to bearer bitmask.
+     *
+     * @param networkTypeBitmask The network type bitmask value
+     * @return The bearer bitmask value.
+     *
+     * @hide
+     */
     public static int convertNetworkTypeBitmaskToBearerBitmask(int networkTypeBitmask) {
         if (networkTypeBitmask == 0) {
             return 0;
@@ -1705,7 +1755,14 @@ public class ServiceState implements Parcelable {
         return bearerBitmask;
     }
 
-    /** @hide */
+    /**
+     * Convert bearer bitmask to network type bitmask.
+     *
+     * @param bearerBitmask The bearer bitmask value.
+     * @return The network type bitmask value.
+     *
+     * @hide
+     */
     public static int convertBearerBitmaskToNetworkTypeBitmask(int bearerBitmask) {
         if (bearerBitmask == 0) {
             return 0;