Give disabled delete vote button a style

Change-Id: I51883c5216db095de965d7e300b3cc214d4d7fe4

polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info.html

diff --git a/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info.html b/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info.html
index 195ddc3..2aead04 100644
--- a/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info.html
+++ b/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info.html
@@ -77,6 +77,9 @@
           width: 2em;
         }
       }
+      gr-button[disabled] iron-icon {
+        color: var(--border-color);
+      }
       gr-account-chip {
         margin-right: .25em;
       }
@@ -127,4 +130,4 @@
     <gr-rest-api-interface id="restAPI"></gr-rest-api-interface>
   </template>
   <script src="gr-label-info.js"></script>
-</dom-module>
\ No newline at end of file
+</dom-module>

polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info.js

diff --git a/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info.js b/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info.js
index 4182977..2fe5f7b1 100644
--- a/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info.js
+++ b/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info.js
@@ -177,4 +177,4 @@
       return '';
     },
   });
-})();
\ No newline at end of file
+})();