Don't reinflate search bar when dialog is already showing

Change https://android-git.corp.google.com/g/27729 started reinflating
the entire search bar every time the search source was changed, to get
around problems with bad state in AutoCompleteTextView
(http://b/issue?id=2132686). This had some side-effects if the
search dialog was already visible, as it is when selecting a
source in "More results" or when presing the search key to go to
QSB from in-app search.

This change changes the reinflation to only happen if the dialog is
not already showing.

Fixes:

http://b/issue?id=2166640
"After selecting More results from suggestions, the search box is no longer visible."

http://b/issue?id=2166675
"Calling QSB with the hardware key does not place focus in the search tab."

http://b/issue?id=2166712
"back key has unexpected behaviour in QSB after selecting "More results" from suggestions."

Change-Id: I8d48149c3e9ad97ec11c49ec7efb356f27dfe4f6

core/java/android/app/SearchDialog.java

@@ -364,10 +364,12 @@ public class SearchDialog extends Dialog implements OnItemClickListener, OnItemS
         mGlobalSearchMode = globalSearch || searchManager.isDefaultSearchable(mSearchable);
         mActivityContext = mSearchable.getActivityContext(getContext());
 
-        createContentView();
-
         // show the dialog. this will call onStart().
-        if (!isShowing()) {            
+        if (!isShowing()) {
+            // Recreate the search bar view every time the dialog is shown, to get rid
+            // of any bad state in the AutoCompleteTextView etc
+            createContentView();
+
             // The Dialog uses a ContextThemeWrapper for the context; use this to change the
             // theme out from underneath us, between the global search theme and the in-app
             // search theme. They are identical except that the global search theme does not