Update k8s_exec and k8s_cp to include container name (#1858)

Update secrets.yml

We need to specify a container in environments that use sidecar injection, like in the case of istio service mesh. If the container is not specified, and a side car is injected so there are multiple containers running in the pod, this task will fail because a container was not specified in a pod with multiple containers.

roles/backup/tasks/postgres.yml

@@ -60,6 +60,7 @@
   k8s_exec:
     namespace: "{{ backup_pvc_namespace }}"
     pod: "{{ ansible_operator_meta.name }}-db-management"
+    container: "{{ ansible_operator_meta.name }}-db-management"
     command: >-
       mkdir -p {{ backup_dir }}
 
@@ -67,6 +68,7 @@
   k8s_exec:
     namespace: "{{ backup_pvc_namespace }}"
     pod: "{{ ansible_operator_meta.name }}-db-management"
+    container: "{{ ansible_operator_meta.name }}-db-management"
     command: >-
       touch {{ backup_dir }}/tower.db
 
@@ -126,6 +128,7 @@
   k8s_exec:
     namespace: "{{ backup_pvc_namespace }}"
     pod: "{{ ansible_operator_meta.name }}-db-management"
+    container: "{{ ansible_operator_meta.name }}-db-management"
     command: |
       bash -c "
       function end_keepalive {