Fixed issues when adding new media and deinitializing media

[sauwming]

There are several issues when adding new media, which need to be fixed:

• Default new added media is initialised as inactive.
  This is because we currently don't set media direction for media reinitialization.

    if (!reinit) {
            /* Initialize default initial media direction as bidirectional. */
            call_med->def_dir = PJMEDIA_DIR_ENCODING_DECODING;
    }

• Currently, the IP version detection is only done from initial offer.

static int get_media_ip_version(pjsua_call_media *call_med)
{
    pjmedia_sdp_session *rem_sdp = call_med->call->async_call.rem_sdp;

• Set the default direction to the specified param->dir when adding video using pjsua_call_set_vid_strm(call_id, PJSUA_CALL_VID_STRM_ADD, param).

There's also another issue with double media deinitialization:

==60122==ERROR: AddressSanitizer: heap-use-after-free on address 0x00010ea8e938 at pc 0x0001064b4ee0 bp 0x00016b9eca30 sp 0x00016b9ec1f0
READ of size 2048 at 0x00010ea8e938 thread T4
    #1 0x104a66804 in pj_memcpy string.h:854
    #2 0x104a77d54 in pjmedia_stream_get_info stream.c:3250
    #3 0x104784d94 in pjsua_aud_stop_stream pjsua_aud.c:563
    #4 0x1047571a0 in stop_media_stream pjsua_media.c:3122
    #5 0x104750924 in stop_media_session pjsua_media.c:3179
    #6 0x10474f664 in pjsua_media_channel_deinit pjsua_media.c:3262
    #7 0x10471dc20 in pjsua_destroy2 pjsua_core.c:1939

0x00010ea8e938 is located 56 bytes inside of 8000-byte region [0x00010ea8e900,0x00010ea90840)
freed by thread T4 here:
    #5 0x104ea9228 in pj_pool_release pool_i.h:102
    #6 0x104ea92ec in pj_pool_safe_release pool_i.h:111
    #7 0x104a751b8 in pjmedia_stream_destroy stream.c:3170
    #8 0x104785564 in pjsua_aud_stop_stream pjsua_aud.c:612
    #9 0x1047571a0 in stop_media_stream pjsua_media.c:3122
    #10 0x104750924 in stop_media_session pjsua_media.c:3179
    #11 0x10474f664 in pjsua_media_channel_deinit pjsua_media.c:3262
    #12 0x1046ed130 in pjsua_call_hangup pjsua_call.c:3123
    #13 0x1047039c4 in pjsua_call_hangup_all pjsua_call.c:4002
    #14 0x10471db9c in pjsua_destroy2 pjsua_core.c:1931

pjsua_call_hangup_all() and pjsua_media_channel_deinit() will deinitialise the media twice.