[calls] flatpak: Add cmocka dependency

[Evangelos Ribeiro Tzaras <devrtz src gnome org>]

commit f86162da039a4e99656fff4735889b0766643263
Author: Evangelos Ribeiro Tzaras <devrtz fortysixandtwo eu>
Date:   Tue Oct 26 10:20:32 2021 +0200

    flatpak: Add cmocka dependency

 org.gnome.Calls.json | 12 ++++++++++++
 1 file changed, 12 insertions(+)
---
diff --git a/org.gnome.Calls.json b/org.gnome.Calls.json
index 598bdf23..dadb87b8 100644
--- a/org.gnome.Calls.json
+++ b/org.gnome.Calls.json
@@ -134,6 +134,18 @@
                 }
             ]
         },
+        {
+            "name" : "cmocka",
+            "buildsystem" : "cmake",
+            "builddir" : true,
+            "sources" : [
+                {
+                    "type" : "archive",
+                    "url" : "https://cmocka.org/files/1.1/cmocka-1.1.5.tar.xz";,
+                    "sha256" : "f0ccd8242d55e2fd74b16ba518359151f6f8383ff8aef4976e48393f77bba8b6"
+                }
+            ]
+        },
         {
             "name" : "libphonenumber",
             "buildsystem" : "cmake-ninja",