[DPB][YANG] Fix cases when boolean is used in different literal cases

* Add boolean as typedef to sonic-types
* Fix boolean in sonic-feature yang model
* Fix boolean in sonic-flex_counter yang model

Signed-off-by: Mykola Gerasymenko <[email protected]>

Author: mykolaxgerasymenko

src/sonic-yang-models/yang-models/sonic-feature.yang

@@ -42,22 +42,22 @@ module sonic-feature{
                 leaf has_timer {
                     description "This configuration identicates if there is
                                 timer associated to this feature";
-                    type boolean;
-                    default false;
+                    type stypes:boolean_type;
+                    default "false";
                 }
 
                 leaf has_global_scope {
                     description "This configuration identicates there will only one service
                                 spawned for the device";
-                    type boolean;
-                    default false;
+                    type stypes:boolean_type;
+                    default "false";
                 }
 
                 leaf has_per_asic_scope {
                     description "This configuration identicates there will only one service
                                 spawned per asic";
-                    type boolean;
-                    default false;
+                    type stypes:boolean_type;
+                    default "false";
                 }
 
                 leaf high_mem_alert {

src/sonic-yang-models/yang-models/sonic-flex_counter.yang

@@ -5,6 +5,10 @@ module sonic-flex_counter {
     namespace "http://github.com/Azure/sonic-flex_counter";
     prefix flex_counter;
 
+    import sonic-types {
+        prefix stypes;
+    }
+
     description "FLEX COUNTER YANG Module for SONiC OS";
 
     revision 2020-04-10 {
@@ -24,7 +28,7 @@ module sonic-flex_counter {
             }
 
             typedef flex_delay_status {
-                type boolean;
+                type stypes:boolean_type;
             }
 
             description "FLEX_COUNTER_TABLE part of config_db.json";

src/sonic-yang-models/yang-templates/sonic-types.yang.j2

@@ -222,6 +222,11 @@ module sonic-types {
         }
     }
 
+    typedef boolean_type {
+        type string {
+            pattern "false|true|False|True";
+        }
+    }
 
 
     /* Required for CVL */