Add API to enable/disable the visual voicemail client

This CL gives the default dialer, apps with carrier privilege, and
apps with MODIFY_PHONE_STATE the ability to enable/disable the visual
voicemail client.

This is a system API for NMR1. It will be revised in O.

Bug: 30709089
Change-Id: Ic24af14a5e3433c13ba8d253ad8504c94bf71c8f

api/system-current.txt

@@ -40540,6 +40540,7 @@ package android.telephony {
     method public boolean isSmsCapable();
     method public boolean isTtyModeSupported();
     method public boolean isVideoCallingEnabled();
+    method public boolean isVisualVoicemailEnabled(android.telecom.PhoneAccountHandle);
     method public boolean isVoiceCapable();
     method public boolean isVoicemailVibrationEnabled(android.telecom.PhoneAccountHandle);
     method public boolean isWorldPhone();
@@ -40553,6 +40554,7 @@ package android.telephony {
     method public boolean setPreferredNetworkTypeToGlobal();
     method public boolean setRadio(boolean);
     method public boolean setRadioPower(boolean);
+    method public void setVisualVoicemailEnabled(android.telecom.PhoneAccountHandle, boolean);
     method public boolean setVoiceMailNumber(java.lang.String, java.lang.String);
     method public void silenceRinger();
     method public boolean supplyPin(java.lang.String);

telephony/java/android/telephony/TelephonyManager.java

@@ -2483,6 +2483,56 @@ public class TelephonyManager {
         return false;
     }
 
+    /**
+     * Enables or disables the visual voicemail client for a phone account.
+     *
+     * <p>Requires that the calling app is the default dialer, or has carrier privileges, or
+     * has permission {@link android.Manifest.permission#MODIFY_PHONE_STATE MODIFY_PHONE_STATE}.
+     * @see #hasCarrierPrivileges
+     *
+     * @param phoneAccountHandle the phone account to change the client state
+     * @param enabled the new state of the client
+     * @hide
+     */
+    @SystemApi
+    public void setVisualVoicemailEnabled(PhoneAccountHandle phoneAccountHandle, boolean enabled){
+        try {
+            ITelephony telephony = getITelephony();
+            if (telephony != null) {
+                telephony.setVisualVoicemailEnabled(mContext.getOpPackageName(), phoneAccountHandle,
+                    enabled);
+            }
+        } catch (RemoteException ex) {
+        } catch (NullPointerException ex) {
+            // This could happen before phone restarts due to crashing
+        }
+    }
+
+    /**
+     * Returns whether the visual voicemail client is enabled.
+     *
+     * <p>Requires Permission:
+     *   {@link android.Manifest.permission#READ_PHONE_STATE READ_PHONE_STATE}
+     *
+     * @param phoneAccountHandle the phone account to check for.
+     * @return {@code true} when the visual voicemail client is enabled for this client
+     * @hide
+     */
+    @SystemApi
+    public boolean isVisualVoicemailEnabled(PhoneAccountHandle phoneAccountHandle){
+        try {
+            ITelephony telephony = getITelephony();
+            if (telephony != null) {
+                return telephony.isVisualVoicemailEnabled(
+                    mContext.getOpPackageName(), phoneAccountHandle);
+            }
+        } catch (RemoteException ex) {
+        } catch (NullPointerException ex) {
+            // This could happen before phone restarts due to crashing
+        }
+        return false;
+    }
+
     /**
      * Enables the visual voicemail SMS filter for a phone account. When the filter is
      * enabled, Incoming SMS messages matching the OMTP VVM SMS interface will be redirected to the

telephony/java/com/android/internal/telephony/ITelephony.aidl

@@ -454,6 +454,12 @@ interface ITelephony {
      */
     int getVoiceMessageCountForSubscriber(int subId);
 
+    oneway void setVisualVoicemailEnabled(String callingPackage,
+            in PhoneAccountHandle accountHandle, boolean enabled);
+
+    boolean isVisualVoicemailEnabled(String callingPackage,
+            in PhoneAccountHandle accountHandle);
+
     // Not oneway, caller needs to make sure the vaule is set before receiving a SMS
     void enableVisualVoicemailSmsFilter(String callingPackage, int subId,
             in VisualVoicemailSmsFilterSettings settings);