fixed isssue: "Connect to Azure" task icon not show in 2020.3.

Author: shenqianjin

PluginsAndFeatures/azure-toolkit-for-intellij/src/com/microsoft/intellij/runner/LinkAzureServiceBeforeRunProvider.java

@@ -59,6 +59,11 @@ public String getDescription(LinkAzureServiceBeforeRunTask task) {
         return DESCRIPTION;
     }
 
+    @Override
+    public @Nullable Icon getTaskIcon(LinkAzureServiceBeforeRunTask task) {
+        return AzureIconLoader.loadIcon(AzureIconSymbol.Common.AZURE);
+    }
+
     @Nullable
     @Override
     public Icon getIcon() {