fix: dropzone height to fill all screen height (#10547)

browser/app/js/uploads/Dropzone.js

@@ -36,7 +36,7 @@ export class Dropzone extends React.Component {
     // Overwrite the default styling from react-dropzone; otherwise it
     // won't handle child elements correctly.
     const style = {
-      height: "100%",
+      flex: "1",
       borderWidth: "0",
       borderStyle: "dashed",
       borderColor: "#fff"

browser/app/less/inc/file-explorer.less

@@ -20,7 +20,8 @@
 	@media(max-width: @screen-sm-max) {
 		padding: 75px 0 80px;
 	}
-
+  display: flex;
+  flex-direction: column;
 	min-height:100vh;
 	overflow: auto;
 }