[Maps] fix propType warnings for source with joins

x-pack/legacy/plugins/maps/public/components/metric_editor.js

@@ -107,7 +107,7 @@ MetricEditor.propTypes = {
     field: PropTypes.string,
     label: PropTypes.string,
   }),
-  fields: PropTypes.object, // indexPattern.fields IndexedArray object
+  fields: PropTypes.array,
   onChange: PropTypes.func.isRequired,
   metricsFilter: PropTypes.func,
 };

x-pack/legacy/plugins/maps/public/components/metrics_editor.js

@@ -92,7 +92,7 @@ export function MetricsEditor({ fields, metrics, onChange, allowMultipleMetrics,
 
 MetricsEditor.propTypes = {
   metrics: PropTypes.array,
-  fields: PropTypes.object, // indexPattern.fields IndexedArray object
+  fields: PropTypes.array,
   onChange: PropTypes.func.isRequired,
   allowMultipleMetrics: PropTypes.bool,
   metricsFilter: PropTypes.func,

x-pack/legacy/plugins/maps/public/components/single_field_select.js

@@ -87,10 +87,7 @@ export function SingleFieldSelect({ fields,
 
 SingleFieldSelect.propTypes = {
   placeholder: PropTypes.string,
-  fields: PropTypes.oneOfType([
-    PropTypes.object, // IndexedArray object
-    PropTypes.array // array of Field objects
-  ]),
+  fields: PropTypes.array,
   onChange: PropTypes.func.isRequired,
   value: PropTypes.string, // fieldName
   filterField: PropTypes.func,

x-pack/legacy/plugins/maps/public/connected_components/layer_panel/join_editor/resources/join_expression.js

@@ -254,7 +254,7 @@ JoinExpression.propTypes = {
 
   // Right field props
   rightValue: PropTypes.string,
-  rightFields: PropTypes.object, // indexPattern.fields IndexedArray object
+  rightFields: PropTypes.array,
   onRightFieldChange: PropTypes.func.isRequired,
 };
 

x-pack/legacy/plugins/maps/public/connected_components/layer_panel/join_editor/resources/metrics_expression.js

@@ -121,7 +121,7 @@ export class MetricsExpression extends Component {
 
 MetricsExpression.propTypes = {
   metrics: PropTypes.array,
-  rightFields: PropTypes.object,  // indexPattern.fields IndexedArray object
+  rightFields: PropTypes.array,
   onChange: PropTypes.func.isRequired,
 };