Adds two user agent tokens for MediaStreamHandler and MediaSessionHandler (#15)

Author: dsilhavy

app/src/main/java/com/fivegmag/a5gmscommonlibrary/helpers/Constants.kt

@@ -49,4 +49,9 @@ object SessionHandlerEvents {
 object ContentTypes {
     const val DASH = "application/dash+xml"
     const val HLS = "application/vnd.apple.mpegurl"
+}
+
+object UserAgentTokens {
+    const val FIVE_G_MS_REL_17_MEDIA_STREAM_HANDLER = "5GMSMediaStreamHandler/17"
+    const val FIVE_G_MS_REL_17_MEDIA_SESSION_HANDLER = "5GMSMediaSessionHandler/17"
 }