fix(list): ng-click changes item width in IE

In IE11, when using `ng-click` on an `md-list-item`, the
width of the list item would be incorrect due to
https://github.com/philipwalton/flexbugs#7-flex-basis-doesnt-account-for-box-sizingborder-box.

Fix CSS to to use `flex: 1 1 auto` instead of `flex: 1`
so that the width is properly calculated.

Fixes #3708.

Author: topherfangio

src/components/list/list.scss

@@ -46,7 +46,7 @@ md-list-item {
   .md-no-style {
     position: relative;
     padding: $list-item-padding-vertical $list-item-padding-horizontal;
-    flex: 1;
+    flex: 1 1 auto;
 
     &.md-button {
       font-size: inherit;