AWS, GCS: Fix issue with Kryo and empty immutable collections

[nastra]

While looking at #13174 I've noticed an issue with Kryo and empty storage credentials.
I've added some tests that reproduce the original issue with Kryo, where the empty immutable collection can't be serded and fails when it is accessed with something like

Cannot read the array length because "this.array" is null
java.lang.NullPointerException: Cannot read the array length because "this.array" is null
	at org.apache.iceberg.relocated.com.google.common.collect.RegularImmutableList.size(RegularImmutableList.java:47)
	at org.apache.iceberg.relocated.com.google.common.collect.Lists.equalsImpl(Lists.java:1039)
	at org.apache.iceberg.relocated.com.google.common.collect.ImmutableList.equals(ImmutableList.java:708)
	at org.assertj.core.internal.StandardComparisonStrategy.areEqual(StandardComparisonStrategy.java:108)
	at org.assertj.core.internal.Objects.areEqual(Objects.java:228)
	at org.assertj.core.internal.Objects.assertEqual(Objects.java:219)
	at org.assertj.core.api.AbstractAssert.isEqualTo(AbstractAssert.java:374)
	at org.assertj.core.api.AbstractIterableAssert.isEqualTo(AbstractIterableAssert.java:4065)
	at org.assertj.core.api.AbstractListAssert.isEqualTo(AbstractListAssert.java:276)
	at org.assertj.core.api.ListAssert.isEqualTo(ListAssert.java:100)
	at org.apache.iceberg.gcp.gcs.GCSFileIOTest.fileIOWithPrefixedStorageClientWithoutCredentialsKryoSerialization(GCSFileIOTest.java:442)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)

This applies to the storageCredentials in GCSFileIO / S3FileIO / ResolvingFileIO

[talatuyarer]

LGTM

[nandorKollar]

nit: the assertions look the same for both Kryo and Java serialisation, would it make sense to use a 'mini-parametrisation', something like a for loop:

for serialisation in {Kryo, Java}
roundTripSerialize with serialisation
perform common assertion logic

[nastra]

yes that might make sense. We do have the same issue across the codebase so I've opened #13237 to address this

[amogh-jahagirdar]

Thanks @nastra , and thank you @talatuyarer @nandorKollar for reviewing. this LGTM