Unhide API isPersistent and getProfileId

Test: cts ApnSettingTest
Bug: 223599330
Change-Id: I1aaf0903e2b27b3a3c919e5c08c509a60053e74e

core/api/current.txt

@@ -43786,6 +43786,7 @@ package android.telephony.data {
     method public int getNetworkTypeBitmask();
     method public String getOperatorNumeric();
     method public String getPassword();
+    method public int getProfileId();
     method public int getProtocol();
     method @Deprecated public java.net.InetAddress getProxyAddress();
     method public String getProxyAddressAsString();
@@ -43793,6 +43794,7 @@ package android.telephony.data {
     method public int getRoamingProtocol();
     method public String getUser();
     method public boolean isEnabled();
+    method public boolean isPersistent();
     method public void writeToParcel(@NonNull android.os.Parcel, int);
     field public static final int AUTH_TYPE_CHAP = 2; // 0x2
     field public static final int AUTH_TYPE_NONE = 0; // 0x0

telephony/java/android/telephony/data/ApnSetting.java

@@ -549,7 +549,6 @@ public class ApnSetting implements Parcelable {
      * Returns the profile id to which the APN saved in modem.
      *
      * @return the profile id of the APN
-     * @hide
      */
     public int getProfileId() {
         return mProfileId;
@@ -558,8 +557,7 @@ public class ApnSetting implements Parcelable {
     /**
      * Returns if the APN setting is persistent on the modem.
      *
-     * @return is the APN setting to be set in modem
-     * @hide
+     * @return {@code true} if the APN setting is persistent on the modem.
      */
     public boolean isPersistent() {
         return mPersistent;