Added additional props for File Picker

Author: gautamdsheth

src/controls/filePicker/FilePicker.tsx

@@ -46,7 +46,7 @@ export class FilePicker extends React.Component<IFilePickerProps, IFilePickerSta
     this.fileSearchService = new FilesSearchService(props.context, this.props.bingAPIKey);
 
     this.state = {
-      panelOpen: false,
+      panelOpen: this.props.isPanelOpen || false,
       organisationAssetsEnabled: false,
       showFullNav: true
     };

src/controls/filePicker/IFilePickerProps.ts

@@ -113,4 +113,12 @@ export interface IFilePickerProps {
    * @default true
    */
   storeLastActiveTab?: boolean;
+  /**
+   * Specifies if the file picker panel is open by default or not
+   */
+  isPanelOpen?: boolean;
+  /**
+   * Handler when file picker has been cancelled.
+   */
+  onCancel?: () => void;
 }