Switch to Display instead of Debug for log sink configs (#31121)

GitOrigin-RevId: 6b5111b2e591c331f15f8617c2e7c6ef87c61184

Author: sshader

crates/common/src/pii.rs

@@ -3,6 +3,7 @@ use std::fmt;
 /// PII is a light wrapper struct that implements Debug by omitting the contents
 /// when printing in prod.
 #[derive(Clone, Copy, Eq, PartialEq)]
+#[cfg_attr(any(test, feature = "testing"), derive(proptest_derive::Arbitrary))]
 pub struct PII<T>(pub T);
 
 impl<T> std::ops::Deref for PII<T> {