Merge pull request #65381 from ostromart/istio-fix-latest-label

Automatic merge from submit-queue (batch tested with PRs 65381, 65751). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Change prometheus versions from latest to tag

**What this PR does / why we need it:**
Istio 0.8.0 yaml references Prometheus components at :latest tag. This affects reproducability and means some versions may not be security scanned.  
https://github.com/kubernetes/kubernetes/issues/65160

cluster/addons/istio/auth/istio-auth.yaml

@@ -2595,7 +2595,7 @@ spec:
           name: istio-statsd-prom-bridge
       containers:
       - name: statsd-prom-bridge
-        image: "gcr.io/istio-release/prom/statsd-exporter:latest"
+        image: "gcr.io/istio-release/prom/statsd-exporter:v0.6.0"
         imagePullPolicy: IfNotPresent
         ports:
         - containerPort: 9102
@@ -3477,7 +3477,7 @@ spec:
 
       containers:
         - name: prometheus
-          image: "gcr.io/istio-release/prom/prometheus:latest"
+          image: "gcr.io/istio-release/prom/prometheus:v2.3.1"
           imagePullPolicy: IfNotPresent
           args:
             - '--storage.tsdb.retention=6h'

cluster/addons/istio/noauth/istio.yaml

@@ -2582,7 +2582,7 @@ spec:
           name: istio-statsd-prom-bridge
       containers:
       - name: statsd-prom-bridge
-        image: "gcr.io/istio-release/prom/statsd-exporter:latest"
+        image: "gcr.io/istio-release/prom/statsd-exporter:v0.6.0"
         imagePullPolicy: IfNotPresent
         ports:
         - containerPort: 9102
@@ -3464,7 +3464,7 @@ spec:
 
       containers:
         - name: prometheus
-          image: "gcr.io/istio-release/prom/prometheus:latest"
+          image: "gcr.io/istio-release/prom/prometheus:v2.3.1"
           imagePullPolicy: IfNotPresent
           args:
             - '--storage.tsdb.retention=6h'