Expose adhoc conference calling API as public.

Bug: 159944852
Test: make
Change-Id: I2cf39a6fd8a02ca4f2d0c83c484ab12bb13f74c3
diff --git a/telecomm/java/android/telecom/Conference.java b/telecomm/java/android/telecom/Conference.java
index d960552..39c3ff9 100644
--- a/telecomm/java/android/telecom/Conference.java
+++ b/telecomm/java/android/telecom/Conference.java
@@ -181,8 +181,8 @@
 
     /**
      * Returns whether this conference is requesting that the system play a ringback tone
-     * on its behalf.
-     * @hide
+     * on its behalf. A ringback tone may be played when an outgoing conference is in the process of
+     * connecting to give the user an audible indication of that process.
      */
     public final boolean isRingbackRequested() {
         return mRingbackRequested;
@@ -329,7 +329,6 @@
     /**
      * Notifies the {@link Conference} of a request to add a new participants to the conference call
      * @param participants that will be added to this conference call
-     * @hide
      */
     public void onAddConferenceParticipants(@NonNull List<Uri> participants) {}
 
@@ -340,7 +339,6 @@
      * the default dialer's {@link InCallService}.
      *
      * @param videoState The video state in which to answer the connection.
-     * @hide
      */
     public void onAnswer(int videoState) {}
 
@@ -360,7 +358,6 @@
      * a request to reject.
      * For managed {@link ConnectionService}s, this will be called when the user rejects a call via
      * the default dialer's {@link InCallService}.
-     * @hide
      */
     public void onReject() {}
 
@@ -380,7 +377,6 @@
 
     /**
      * Sets state to be ringing.
-     * @hide
      */
     public final void setRinging() {
         setState(Connection.STATE_RINGING);
@@ -506,7 +502,6 @@
      * that do not play a ringback tone themselves in the conference's audio stream.
      *
      * @param ringback Whether the ringback tone is to be played.
-     * @hide
      */
     public final void setRingbackRequested(boolean ringback) {
         if (mRingbackRequested != ringback) {
@@ -773,7 +768,6 @@
      *
      * @param disconnectCause The disconnect cause, ({@see android.telecomm.DisconnectCause}).
      * @return A {@code Conference} which indicates failure.
-     * @hide
      */
     public @NonNull static Conference createFailedConference(
             @NonNull DisconnectCause disconnectCause, @NonNull PhoneAccountHandle phoneAccount) {