samples: zephyr: system_off: system_off fixes

For reasons other than system off, the retained data should be cleared.

Signed-off-by: Adam Kondraciuk <[email protected]>

Author: adamkondraciuk

samples/zephyr/boards/nordic/system_off/sample.yaml

@@ -40,7 +40,7 @@ tests:
       ordered: true
       regex:
         - "system off demo"
-        - "Retained data: INVALID"
+        - "Retained data: valid"
         - "Boot count: 1"
         - "Off count: 0"
         - "Active Ticks:"
@@ -83,7 +83,7 @@ tests:
       ordered: true
       regex:
         - "system off demo"
-        - "Retained data: INVALID"
+        - "Retained data: valid"
         - "Boot count: 1"
         - "Off count: 0"
         - "Active Ticks:"