added hover to address copy button

Author: NidhiKJha

ui/components/multichain/app-header/app-header.js

@@ -320,6 +320,7 @@ export const AppHeader = ({ location }) => {
                       title={copied ? t('addressCopied') : null}
                     >
                       <ButtonBase
+                        className="multichain-app-header__address-copy-button"
                         onClick={() => handleCopy(checksummedCurrentAddress)}
                         size={ButtonBaseSize.Sm}
                         backgroundColor={BackgroundColor.transparent}

ui/components/multichain/app-header/index.scss

@@ -38,6 +38,14 @@
     }
   }
 
+  &__address-copy-button {
+    &:not([disabled]):hover,
+    &:not([disabled]):focus {
+      box-shadow: none;
+      background: var(--color-background-default-hover);
+    }
+  }
+
   &__lock-contents {
     flex-flow: row nowrap;
     height: 68px;