[UI] License Agreement content truncated and Close icon doesn't work

[williamlin-suse]

Manager Build Version: 5.5.0-rc1

Issue Detail:
Close icon doesn't work on License Agreement window & License Agreement content is not fully displayed

Steps To Reproduce:
1, Deploy NV
2. On login page, click "End User License Agreement" link
3. UI switches to "End User License Agreement for NeuVector Products" dialog
4. Notice the content under "GENERAL LICENSE GRANT" is truncated
5. click X (to close "End User License Agreement" dialog)

Actual Result:
After step 5, "End User License Agreement" dialog doesn't close & there is no way to leave the dialog unless close the browser tab

Expected Result:

1. "End User License Agreement for NeuVector Products" dialog is fully displayed or a scroll bar is provided.
2. "End User License Agreement" dialog is closed after clicking X

[xingzhang-suse]

After fixed
The close button works, as the event handler is moved into button element
The agreement content is wrapped by scrollable block.