[vala/0.54] gstreamer: Cherry-pick bindings fixes from 0.56

[Rico Tzschichholz <ricotz src gnome org>]

commit 4447f4373a25875047e14e29ec46e56dc92092d4
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Wed Dec 15 16:27:56 2021 +0100

    gstreamer: Cherry-pick bindings fixes from 0.56

 vapi/gstreamer-base-1.0.vapi | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/vapi/gstreamer-base-1.0.vapi b/vapi/gstreamer-base-1.0.vapi
index 6746f5c5a..223ddcf65 100644
--- a/vapi/gstreamer-base-1.0.vapi
+++ b/vapi/gstreamer-base-1.0.vapi
@@ -878,8 +878,8 @@ namespace Gst {
                        [CCode (array_length = false, cname = "gst_bit_writer_free_and_get_data")]
                        [DestroysInstance]
                        public uint8[] free_and_get_data ();
-                       [CCode (cname = "gst_bit_writer_get_data")]
-                       public uint8 get_data ();
+                       [CCode (array_length = false, cname = "gst_bit_writer_get_data")]
+                       public unowned uint8[] get_data ();
                        [CCode (cname = "gst_bit_writer_get_remaining")]
                        public uint get_remaining ();
                        [CCode (cname = "gst_bit_writer_get_size")]