Add fallback for random number generator

`getrandom()` is available since Linux 3.17 (2014/10/05) yet there are older devices that don't
meet this requirement.

Closes #22691.
PR #22723.

src/base/utils/random.cpp

@@ -42,7 +42,7 @@
 
 uint32_t Utils::Random::rand(const uint32_t min, const uint32_t max)
 {
-    static RandomLayer layer;
+    static const RandomLayer layer;
 
     // new distribution is cheap: https://stackoverflow.com/a/19036349
     std::uniform_int_distribution<uint32_t> uniform(min, max);