chore(env): Adding required env inside chaosengine (#479)

Signed-off-by: shubhamchaudhary <shubham@chaosnative.com>

charts/generic/pod-cpu-hog-exec/engine.yaml

@@ -16,10 +16,15 @@ spec:
       spec:
         components:
           env:
+            - name: TOTAL_CHAOS_DURATION
+              value: '60' # in seconds
+
             #number of cpu cores to be consumed
             #verify the resources the app has been launched with
             - name: CPU_CORES
               value: '1'
 
-            - name: TOTAL_CHAOS_DURATION
-              value: '60' # in seconds
+             ## Percentage of total pods to target
+            - name: PODS_AFFECTED_PERC
+              value: ''    
+