Create widget resize frame after spring loaded workspace has exited.

Before, the resize frame was created as soon as a widget was dropped,
but this caused it to be in the wrong spot after the spring loaded
mode exited. Instead, we should wait until the workspace is back to
normal before creating the resize frame.

Bug: 24192073

Change-Id: I8d87febcc4ec7e3c44d50135184c3a837d7cd960