Add unit test to fetchChucnkSizeKiB

Author: cemakd

pkg/gce-pd-csi-driver/cache_test.go

@@ -31,6 +31,11 @@ func TestFetchChunkSizeKiB(t *testing.T) {
 			cacheSize:    "1",
 			expChunkSize: "160KiB", //range defined in fetchChunkSizeKiB - min 160 KiB
 		},
+		{
+			name:         "chunk size with GiB string parses correctly",
+			cacheSize:    "375GiB",
+			expChunkSize: "384KiB",
+		},
 		{
 			name:         "invalid cacheSize",
 			cacheSize:    "fdfsdKi",