Add stable uuid generation for playback

sdk/internal/recording/recording.go

@@ -211,7 +211,20 @@ func (r *Recording) Now() time.Time {
 func (r *Recording) UUID() uuid.UUID {
 	r.initRandomSource()
 
-	return uuid.FromSource(r.src)
+	if r.Mode == Live {
+		return uuid.New()
+	}
+
+	u := uuid.UUID{}
+	// Set all bits to randomly (or pseudo-randomly) chosen values.
+	// math/rand.Read() is no-fail so we omit any error checking.
+	rnd := rand.New(r.src)
+	rnd.Read(u[:])
+	u[8] = (u[8] | 0x40) & 0x7F // u.setVariant(ReservedRFC4122)
+
+	var version byte = 4
+	u[6] = (u[6] & 0xF) | (version << 4) // u.setVersion(4)
+	return u
 }
 
 // GenerateAlphaNumericID will generate a recorded random alpha numeric id