flatpak: Fix flatpak build

Mostly updating of dependencies.

Notable changes:
- Build abseil with position independent code
- Drop patch for libphonenumber and use -DREGENERATE_METADATA=OFF
  instead to drop the java build dependency
- Drop gstreamer as it's included in the runtime already
- Drop cmocka as we're about to drop it's usage completely anyway

org.gnome.Calls.json

@@ -94,8 +94,8 @@
             "sources" : [
                 {
                     "type" : "archive",
-                    "url" : "https://boostorg.jfrog.io/artifactory/main/release/1.72.0/source/boost_1_72_0.tar.bz2",
-                    "sha256" : "59c9b274bc451cf91a9ba1dd2c7fdcaf5d60b1b3aa83f2c9fa143417cc660722"
+                    "url" : "https://boostorg.jfrog.io/artifactory/main/release/1.74.0/source/boost_1_74_0.tar.bz2",
+                    "sha256" : "83bfc1507731a0906e387fc28b7ef5417d591429e51e788417fe9ff025e116b1"
                 }
             ],
             "build-commands" : [
@@ -130,41 +130,44 @@
             "sources" : [
                 {
                     "type" : "archive",
-                    "url" : "https://github.com/protocolbuffers/protobuf/releases/download/v3.6.1/protobuf-cpp-3.6.1.tar.gz",
-                    "sha256" : "b3732e471a9bb7950f090fd0457ebd2536a9ba0891b7f3785919c654fe2a2529"
+                    "url" : "https://github.com/protocolbuffers/protobuf/releases/download/v3.12.4/protobuf-cpp-3.12.4.tar.gz",
+                    "sha256" : "ccfbaaba52f67e0e6536a05f3df3f6618620d255513cfca3a07f5935b624e26b"
                 }
             ]
         },
         {
-            "name" : "cmocka",
+            "name" : "abseil",
             "buildsystem" : "cmake",
-            "builddir" : true,
+            "config-opts" : [
+                "-DCMAKE_CXX_STANDARD=17",
+                "-DCMAKE_POSITION_INDEPENDENT_CODE=ON"
+            ],
             "sources" : [
                 {
                     "type" : "archive",
-                    "url" : "https://cmocka.org/files/1.1/cmocka-1.1.5.tar.xz",
-                    "sha256" : "f0ccd8242d55e2fd74b16ba518359151f6f8383ff8aef4976e48393f77bba8b6"
+                    "url" : "https://github.com/abseil/abseil-cpp/archive/refs/tags/20220623.1.tar.gz",
+                    "sha256" : "91ac87d30cc6d79f9ab974c51874a704de9c2647c40f6932597329a282217ba8"
                 }
             ]
         },
         {
             "name" : "libphonenumber",
-            "buildsystem" : "cmake-ninja",
+            "buildsystem" : "cmake",
+            "config-opts" : [
+                "-DCMAKE_CXX_STANDARD=17",
+                "-DREGENERATE_METADATA=OFF"
+            ],
             "sources" : [
                 {
                     "type" : "archive",
-                    "url" : "https://github.com/google/libphonenumber/archive/v8.10.16.tar.gz",
-                    "sha256" : "0cd9baf788dc7a7cca94ecbd43d0a562c4acf21f234d66d756574be89edf14c5"
+                    "url" : "https://github.com/google/libphonenumber/archive/refs/tags/v8.12.54.tar.gz",
+                    "sha256" : "cf3d531a6b097cad508c475888bcf042ff15fabc6be05e3f817224ae8512ce63"
                 },
                 {
                     "type" : "shell",
                     "commands" : [
                         "sed -i -e 's/\${\${NAME}_BIN}-NOTFOUND/\${NAME}_BIN-NOTFOUND/' cpp/CMakeLists.txt"
                     ]
-                },
-                {
-                    "type" : "patch",
-                    "path" : "build-aux/fix-libphonenumber-build.patch"
                 }
             ],
             "subdir" : "cpp"
@@ -222,6 +225,7 @@
                 "-DENABLE_INSTALLED_TESTS=OFF",
                 "-DENABLE_GTK_DOC=OFF",
                 "-DENABLE_EXAMPLES=OFF",
+                "-DENABLE_OAUTH2=OFF",
                 "-DWITH_PHONENUMBER:PATH=/"
             ],
             "sources" : [
@@ -286,17 +290,6 @@
                 }
             ]
         },
-        {
-            "name" : "gstreamer",
-            "buildsystem" : "meson",
-            "sources" : [
-                {
-                    "type" : "archive",
-                    "url" : "https://gitlab.freedesktop.org/gstreamer/gstreamer/-/archive/1.19.3/gstreamer-1.19.3.tar.gz",
-                    "sha256" : "f155fe7335de78988dc6264524e716b6e4f02be27d106b765c187cc2c1d5de7e"
-                }
-            ]
-        },
         {
             "name" : "sofia-sip",
             "buildsystem" : "autotools",