ProcMount validation and testing

Signed-off-by: Serguei Bezverkhi <sbezverk@cisco.com>

pkg/apis/core/fuzzer/fuzzer.go

@@ -354,6 +354,10 @@ var Funcs = func(codecs runtimeserializer.CodecFactory) []interface{} {
 				c.Fuzz(&sc.Capabilities.Add)
 				c.Fuzz(&sc.Capabilities.Drop)
 			}
+			if sc.ProcMount == nil {
+				defProcMount := core.DefaultProcMount
+				sc.ProcMount = &defProcMount
+			}
 		},
 		func(s *core.Secret, c fuzz.Continue) {
 			c.FuzzNoCustom(s) // fuzz self without calling this function again