Benchmark: get dav1d version as resValue

This is to send the dav1d version in use to the benchmark.

application/vlc-android/build.gradle

@@ -23,6 +23,7 @@ android {
         resValue "string", "build_host", hostName()
         resValue "string", "build_revision", revision()
         resValue "string", "changelog", changelog()
+        resValue "string", "dav1d_version", dav1dVersion()
         resValue 'string', 'tv_provider_authority', "${rootProject.ext.appId}.tv"
         buildConfigField 'String', 'LIBVLC_VERSION', "\"${rootProject.ext.libvlcVersion}\""
         buildConfigField 'String', 'ML_VERSION', "\"${rootProject.ext.medialibraryVersion}\""
@@ -242,6 +243,18 @@ def revision() {
     return code.toString()
 }
 
+def dav1dVersion() {
+    def code = new ByteArrayOutputStream()
+    if (file("../../libvlcjni/vlc/contrib/src/dav1d/rules.mak").exists()) {
+        exec {
+            commandLine 'bash', '-c', 'grep "DAV1D_VERSION := " ../../libvlcjni/vlc/contrib/src/dav1d/rules.mak | cut -d = -f2'
+            standardOutput = code
+        }
+        return code.toString().replaceAll(" ", "")
+    }
+    return "0.0.0"
+}
+
 /**
  * Generate a changelog string from the NEWS file
  * @return a string containing the latest changelog entry