Correctly setting the value of manual_review

Fixing manual_review variable being set from automaticReview input box
from the user diff preference dialog box.

Bug: Issue 10757
Change-Id: Ibb89428b742837f1d7011d73ff38cf29f1740c70
(cherry picked from commit 3353108f84)

polygerrit-ui/app/elements/shared/gr-diff-preferences/gr-diff-preferences.html

@@ -135,7 +135,7 @@ limitations under the License.
           <input
               id="automaticReviewInput"
               type="checkbox"
-              checked$="[[diffPrefs.manual_review]]"
+              checked$="[[!diffPrefs.manual_review]]"
               on-change="_handleAutomaticReviewTap">
         </span>
       </section>

polygerrit-ui/app/elements/shared/gr-diff-preferences/gr-diff-preferences.js

@@ -65,7 +65,7 @@
 
     _handleAutomaticReviewTap() {
       this.set('diffPrefs.manual_review',
-          this.$.automaticReviewInput.checked);
+          !this.$.automaticReviewInput.checked);
       this._handleDiffPrefsChanged();
     },
 

polygerrit-ui/app/elements/shared/gr-diff-preferences/gr-diff-preferences_test.html

@@ -96,7 +96,7 @@ limitations under the License.
           .firstElementChild.checked, diffPreferences.syntax_highlighting);
       assert.equal(
           valueOf('Automatically mark viewed files reviewed', 'diffPreferences')
-              .firstElementChild.checked, diffPreferences.manual_review);
+              .firstElementChild.checked, !diffPreferences.manual_review);
       assert.equal(valueOf('Ignore Whitespace', 'diffPreferences')
           .firstElementChild.bindValue, diffPreferences.ignore_whitespace);