Fix filtering when multiple project detail lists

There was an issue where the path passed to the gr-list-view was not
updated when the detail list switched from branches to tags or vice
versa. This is fixed by passing the detailType as a parameter in the
_getPath function, so that it gets updated when the detailType is
updated.

Change-Id: I937c9aea977f2b1028a2fa5f143b71add6b59b4c

polygerrit-ui/app/elements/shared/gr-list-view/gr-list-view.html

@@ -60,7 +60,7 @@ limitations under the License.
         <input is="iron-input"
             type="text"
             id="filter"
-            bind-value="{{_filter}}">
+            bind-value="{{filter}}">
       </div>
       <div id="createNewContainer"
           class$="[[_computeCreateClass(createNew)]]">

polygerrit-ui/app/elements/shared/gr-list-view/gr-list-view.js

@@ -23,7 +23,7 @@
       createNew: Boolean,
       items: Array,
       itemsPerPage: Number,
-      _filter: {
+      filter: {
         type: String,
         observer: '_filterChanged',
       },