Fix bugs for Widgets picker Search UI.

- On orientation change, clear search bar.
- Change text and search bar color to make similar to mocks/ all apps search bar.
- Fix search recycler view visual bugs.
- If back is pressed in search mode, exit search mode instead of exiting widget picker.

Test: Manually seen widget picker on phone.
Bug: 183103133
Bug: 183103936
Bug: 183115050
Bug: 157286785
Change-Id: I056f089eada84d00133038f4a3d7b18bc51be564
diff --git a/res/layout/widgets_search_bar.xml b/res/layout/widgets_search_bar.xml
index cf693bb..021058b 100644
--- a/res/layout/widgets_search_bar.xml
+++ b/res/layout/widgets_search_bar.xml
@@ -19,12 +19,15 @@
         android:hint="@string/widgets_full_sheet_search_bar_hint"
         android:maxLines="1"
         android:layout_weight="1"
-        android:inputType="text"/>
+        android:inputType="text"
+        android:textColor="?android:attr/textColorSecondary"
+        android:textColorHint="?android:attr/textColorTertiary"/>
 
     <ImageButton
         android:id="@+id/widgets_search_cancel_button"
         android:layout_height="wrap_content"
         android:layout_width="wrap_content"
+        android:padding="8dp"
         android:src="@drawable/ic_gm_close_24"
         android:background="?android:selectableItemBackground"
         android:layout_gravity="center"