fix(autocomplete): show hover style on selected options

Author: kara

src/lib/autocomplete/_autocomplete-theme.scss

@@ -9,7 +9,11 @@
     color: mat-color($foreground, text);
 
     .mat-option {
-      &.mat-selected:not(.mat-active) {
+      // We only want to override the background for selected
+      // options if they are *not* in hover or focus state. This
+      // change has to be made here because base option styles
+      // are shared between the autocomplete and the select.
+      &.mat-selected:not(.mat-active):not(:hover) {
         background: mat-color($background, card);
         color: mat-color($foreground, text);
       }