Rename and move func checking if amr mode is explicitly configured

The previous naming was quite confusing, since the function is not
really checking whether a conversion is needed, but rather whether the
codec has the AMR RTP mode defined explicitly and hence forced.

The previous naming didn't harm because the amr_oa_bwe_convert also
supports the conversion path OA<->OA and BE<->BE.
Hence nowadays the amr_oa_bwe_convert() function is called always if the
dst conn has its codec with AMR RTP mode explicitly set, no matter if
the src and dst conn have the same mode.

Related: SYS#6161
Change-Id: I8dce3038ebccf5e1e37e2908070a67d66693a96f
diff --git a/src/libosmo-mgcp/mgcp_codec.c b/src/libosmo-mgcp/mgcp_codec.c
index 38aa0a7..1a8d26a 100644
--- a/src/libosmo-mgcp/mgcp_codec.c
+++ b/src/libosmo-mgcp/mgcp_codec.c
@@ -345,6 +345,18 @@
 	return -EINVAL;
 }
 
+/* Check if the codec has a specific AMR mode (octet-aligned or bandwith-efficient) set. */
+bool mgcp_codec_amr_align_mode_is_indicated(const struct mgcp_rtp_codec *codec)
+{
+	if (codec->param_present == false)
+		return false;
+	if (!codec->param.amr_octet_aligned_present)
+		return false;
+	if (strcmp(codec->subtype_name, "AMR") != 0)
+		return false;
+	return true;
+}
+
 /* Return true if octet-aligned is set in the given codec. Default to octet-aligned=0, i.e. bandwidth-efficient mode.
  * See RFC4867 "RTP Payload Format for AMR and AMR-WB" sections "8.1. AMR Media Type Registration" and "8.2. AMR-WB
  * Media Type Registration":