feat: enable http2 in sandbox

Author: MacMur85

infrastructure/tf-core/environments/sandbox.tfvars

@@ -325,7 +325,7 @@ function_apps = {
   enable_appsrv_storage         = "false"
   ftps_state                    = "Disabled"
   https_only                    = true
-  http2_enabled                 = false
+  http2_enabled                 = true
   remote_debugging_enabled      = false
   storage_uses_managed_identity = null
   worker_32bit                  = false