fix(kube-runtime): setup backoff with builder pattern (#1603)

* fix(kube-runtime): setup backoff with builder pattern

Filling the fields manually and leaving the current_interval out
meant that the current_interval is set to its default rather than
track the initial_interval
The builder addresses this for us by setting it on the build method.

Signed-off-by: Tiago Castro <tiagolobocastro@gmail.com>

* test(coverage): add test for default backoff

Signed-off-by: Tiago Castro <tiagolobocastro@gmail.com>

* chore: run just fmt

Signed-off-by: Tiago Castro <tiagolobocastro@gmail.com>

* revert: add test for default backoff

This reverts commit fd3d1c2.

Signed-off-by: Tiago Castro <tiagolobocastro@gmail.com>

---------

Signed-off-by: Tiago Castro <tiagolobocastro@gmail.com>

kube-runtime/src/watcher.rs

@@ -898,14 +898,13 @@ type Strategy = ResetTimerBackoff<ExponentialBackoff>;
 impl Default for DefaultBackoff {
     fn default() -> Self {
         Self(ResetTimerBackoff::new(
-            backoff::ExponentialBackoff {
-                initial_interval: Duration::from_millis(800),
-                max_interval: Duration::from_secs(30),
-                randomization_factor: 1.0,
-                multiplier: 2.0,
-                max_elapsed_time: None,
-                ..ExponentialBackoff::default()
-            },
+            backoff::ExponentialBackoffBuilder::new()
+                .with_initial_interval(Duration::from_millis(800))
+                .with_max_interval(Duration::from_secs(30))
+                .with_randomization_factor(1.0)
+                .with_multiplier(2.0)
+                .with_max_elapsed_time(None)
+                .build(),
             Duration::from_secs(120),
         ))
     }