title: Material UI Select override Position in theme
body: <p>I want to override position of dropdown of selectfield in the theme (to not have to implement it on each select).  </p>
  
  <p>I have try:</p>
  
  <pre><code>createMuiTheme({
    overrides: {
      MuiSelect: {
        select:{
          MenuProps: {
            getContentAnchorEl: null,
              anchorOrigin: {
                vertical: "bottom",
                  horizontal: "left",
              }
            }
          }
        }
      }
    }
  });
  </code></pre>
  
  <p>Position of dropdown is not override. 
  I also try to replace <code>select</code> by <code>selectMenu</code> but nothing happen... </p>
  
  <p>When I pass directly to compnent props, it's working: </p>
  
  <pre><code>&lt;Select
    ...otherProperties, 
    MenuProps={{
      getContentAnchorEl: null,
      anchorOrigin: {
        vertical: "bottom",
        horizontal: "left",
      }
    }}
  &gt;
    ...childs
  &lt;/Select&gt;
  </code></pre>
  
  <p>How can I achived override this props for all select? </p>
  
  <p>For informmation I am using: </p>
  
  <pre><code>"react": "^16.12.0",
  "@material-ui/core": "^4.9.10", 
  "typescript": "3.6.3",
  </code></pre>
  
  <p>Thanks in advance</p>