test: fixed various flaky tests (#1009)

- Removed test cases which required access to `/root` from the
  `pkg/util` package.

- Fixed flaky `PodDisruptionBudget` test.

- Fixed a typo in `PersistentVolumeClaim` test.

Signed-off-by: VaibhavMalik4187 <vaibhavmalik2018@gmail.com>

pkg/util/util_test.go

@@ -423,11 +423,6 @@ func TestFileExists(t *testing.T) {
 			filePath:  "./util.go",
 			isPresent: true,
 		},
-		{
-			filePath:  "/root/temp.go",
-			isPresent: false,
-			err:       "permission denied",
-		},
 	}
 	for _, tt := range tests {
 		tt := tt
@@ -455,10 +450,6 @@ func TestEnsureDirExists(t *testing.T) {
 		{
 			dir: "./",
 		},
-		{
-			dir: "/root/tmp/",
-			err: "permission denied",
-		},
 	}
 	for _, tt := range tests {
 		tt := tt