Dismissing suggestion popup if options menu is invoked.

Currently if suggestion popup is visible and options menu is
invoked from hardware options button then in that case suggestion
popup and options menu are overlapping.
Added code to dismiss suggestion popup if options menu is shown.

BUG=412757

Review URL: https://codereview.chromium.org/552373004

Cr-Commit-Position: refs/heads/master@{#294575}

chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellActivity.java

@@ -281,6 +281,7 @@ public class ChromeShellActivity extends Activity implements AppMenuPropertiesDe
     @Override
     public boolean onKeyDown(int keyCode, KeyEvent event) {
         if (keyCode == KeyEvent.KEYCODE_MENU && event.getRepeatCount() == 0) {
+            if (mToolbar != null) mToolbar.hideSuggestions();
             mAppMenuHandler.showAppMenu(findViewById(R.id.menu_button), true, false);
             return true;
         }