Simplify detection of meta key in tandem with enter key

Thanks @lukevmorris for the tip

ui/src/dashboards/components/CellEditorOverlay.js

@@ -60,8 +60,6 @@ class CellEditorOverlay extends Component {
       axes,
       colorSingleStatText: colorsTypeContainsText,
       colors: validateColors(colors, type, colorsTypeContainsText),
-      metaKeyDown: false,
-      enterKeyDown: false,
     }
   }
 
@@ -449,29 +447,9 @@ class CellEditorOverlay extends Component {
   }
 
   handleHotKeyDown = e => {
-    if (e.key === 'Meta') {
-      this.setState({metaKeyDown: true})
-    }
-    if (e.key === 'Enter') {
-      this.setState({enterKeyDown: true})
-    }
-  }
-
-  handleHotKeyUp = e => {
-    if (e.key === 'Meta') {
-      this.setState({metaKeyDown: false})
-
-      if (this.state.enterKeyDown === true && e.target === this.overlayRef) {
+    if (e.key === 'Enter' && e.metaKey && e.target === this.overlayRef) {
       this.handleSaveCell()
     }
-    }
-    if (e.key === 'Enter') {
-      this.setState({enterKeyDown: false})
-
-      if (this.state.metaKeyDown === true && e.target === this.overlayRef) {
-        this.handleSaveCell()
-      }
-    }
     if (e.key === 'Escape' && e.target === this.overlayRef) {
       this.props.onCancel()
     }
@@ -510,7 +488,6 @@ class CellEditorOverlay extends Component {
       <div
         className={OVERLAY_TECHNOLOGY}
         onKeyDown={this.handleHotKeyDown}
-        onKeyUp={this.handleHotKeyUp}
         tabIndex="0"
         ref={r => (this.overlayRef = r)}
       >