Updating extension id regex (Azure#15152)

Author: priyankajayaswal1

specification/agrifood/data-plane/Microsoft.AgFoodPlatform/preview/2021-03-31-preview/agfood.json

@@ -9015,7 +9015,7 @@
             "description": "Id of the weather extension. This signifies the source from where the weather data is fetched (eg. DTN.ClearAg).",
             "required": true,
             "type": "string",
-            "pattern": "^[A-za-z]{3,50}[.][A-za-z]{3,100}$"
+            "pattern": "^[a-zA-Z]{3,50}[.][a-zA-Z]{3,100}$"
           },
           {
             "in": "query",
@@ -12093,7 +12093,7 @@
           "description": "Id of the weather extension. This signifies the source from where the weather data is fetched (eg. DTN.ClearAg).",
           "maxLength": 100,
           "minLength": 2,
-          "pattern": "^[A-za-z]{3,50}[.][A-za-z]{3,100}$",
+          "pattern": "^[a-zA-Z]{3,50}[.][a-zA-Z]{3,100}$",
           "type": "string"
         },
         "extensionApiName": {
@@ -12204,7 +12204,7 @@
           "description": "Id of the weather extension. This signifies the source from where the weather data was fetched (eg. DTN.ClearAg).",
           "maxLength": 100,
           "minLength": 2,
-          "pattern": "^[A-za-z]{3,50}[.][A-za-z]{3,100}$",
+          "pattern": "^[a-zA-Z]{3,50}[.][a-zA-Z]{3,100}$",
           "type": "string"
         },
         "farmerId": {

specification/agrifood/resource-manager/Microsoft.AgFoodPlatform/preview/2020-05-12-preview/agfood.json

@@ -382,7 +382,7 @@
             "description": "farmBeatsExtensionId to be queried.",
             "required": true,
             "type": "string",
-            "pattern": "^[A-za-z]{3,50}[.][A-za-z]{3,100}$"
+            "pattern": "^[a-zA-Z]{3,50}[.][a-zA-Z]{3,100}$"
           },
           {
             "$ref": "../../../../../common-types/resource-management/v2/types.json#/parameters/ApiVersionParameter"
@@ -833,7 +833,7 @@
       "properties": {
         "extensionId": {
           "description": "Extension Id.",
-          "pattern": "^[A-za-z]{3,50}[.][A-za-z]{3,100}$",
+          "pattern": "^[a-zA-Z]{3,50}[.][a-zA-Z]{3,100}$",
           "type": "string",
           "readOnly": true
         },
@@ -973,7 +973,7 @@
           "description": "FarmBeatsExtension ID.",
           "maxLength": 100,
           "minLength": 2,
-          "pattern": "^[A-za-z]{3,50}[.][A-za-z]{3,100}$",
+          "pattern": "^[a-zA-Z]{3,50}[.][a-zA-Z]{3,100}$",
           "type": "string",
           "readOnly": true
         },