Fix talkback issue on collapsed condition card

When condition card is collapsed, there are only showing icons.
Accessibility can't speak meaningful information after tap it. Use
existed condition expend string to assign content description.

Fixes:128897141
Test: manual
Change-Id: I49bc1ee8af424e90aac6555829c545914355862b

res/layout/homepage_condition_header.xml

@@ -19,6 +19,7 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
+    android:contentDescription="@string/condition_expand_show"
     style="@style/ContextualCardStyle">
 
     <LinearLayout