Add support for dropping fg video call on answer of audio call.

Adding two new carrier config options:
1. treat_downgraded_video_calls_as_video_calls_bool - when there is an ongoing
call which was previously a video call (or is currently video call), some
carriers require that this is treated as if it is a video call for
telephony logic such as in (2).
2. drop_video_call_when_answering_audio_call_bool - if the user is in an
active video call (see (1)) over wifi, and an incoming audio call comes in,
when this carrier config option is "TRUE", the video call will be dropped
when the audio call is answered.

Adding new connection extra to indicate to the dialer app that answering
a ringing call will cause the current active video call to drop.

Bug: 29275420
Change-Id: Ied5dbabc8ff09045ba41c5eba2136adad10db80e
diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index 2c96b3c..2458cc8 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -787,6 +787,27 @@
     public static final String KEY_RATCHET_RAT_FAMILIES =
             "ratchet_rat_families";
 
+    /**
+     * Flag indicating whether some telephony logic will treat a call which was formerly a video
+     * call as if it is still a video call.  When {@code true}:
+     * <p>
+     * Logic which will automatically drop a video call which takes place over WIFI when a
+     * voice call is answered (see {@link #KEY_DROP_VIDEO_CALL_WHEN_ANSWERING_AUDIO_CALL_BOOL}.
+     * <p>
+     * Logic which determines whether the user can use TTY calling.
+     */
+    public static final String KEY_TREAT_DOWNGRADED_VIDEO_CALLS_AS_VIDEO_CALLS_BOOL =
+            "treat_downgraded_video_calls_as_video_calls_bool";
+
+    /**
+     * When {@code true}, if the user is in an ongoing video call over WIFI and answers an incoming
+     * audio call, the video call will be disconnected before the audio call is answered.  This is
+     * in contrast to the usual expected behavior where a foreground video call would be put into
+     * the background and held when an incoming audio call is answered.
+     */
+    public static final String KEY_DROP_VIDEO_CALL_WHEN_ANSWERING_AUDIO_CALL_BOOL =
+            "drop_video_call_when_answering_audio_call_bool";
+
     /** The default value for every variable. */
     private final static PersistableBundle sDefaults;
 
@@ -938,6 +959,8 @@
         // Order is important - lowest precidence first
         sDefaults.putStringArray(KEY_RATCHET_RAT_FAMILIES,
                 new String[]{"1,2","7,8,12","3,11,9,10,15","14,19"});
+        sDefaults.putBoolean(KEY_TREAT_DOWNGRADED_VIDEO_CALLS_AS_VIDEO_CALLS_BOOL, true);
+        sDefaults.putBoolean(KEY_DROP_VIDEO_CALL_WHEN_ANSWERING_AUDIO_CALL_BOOL, true);
     }
 
     /**
diff --git a/telephony/java/com/android/ims/ImsCallProfile.java b/telephony/java/com/android/ims/ImsCallProfile.java
index 92b70e8..65254d8 100644
--- a/telephony/java/com/android/ims/ImsCallProfile.java
+++ b/telephony/java/com/android/ims/ImsCallProfile.java
@@ -448,6 +448,15 @@
     }
 
     /**
+     * Determines if the {@link ImsCallProfile} represents a video call.
+     *
+     * @return {@code true} if the profile is for a video call, {@code false} otherwise.
+     */
+    public boolean isVideoCall() {
+        return VideoProfile.isVideo(getVideoStateFromCallType(mCallType));
+    }
+
+    /**
      * Determines if a video state is set in a video state bit-mask.
      *
      * @param videoState The video state bit mask.