Remove checks for Activity Context when creating SearchManager

Since https://android-git.corp.google.com/g/3880
all activities create a SearchManager object, to handle
saving and restoring the search dialog. This broke
ActivityUnitTestCase, since ApplicationContext.getSearchManager()
threw an exception in non-activity contexts.
This change removes the activity context check from
getSearchManager(). Since SearchManager is now just a thin
wrapper for SearchManagerService, there shouldn't be anything
activity-specific in it.

Fixes http://b/issue?id=1926254

core/java/android/app/ApplicationContext.java

@@ -1037,11 +1037,6 @@ class ApplicationContext extends Context {
     }
 
     private SearchManager getSearchManager() {
-        // This is only useable in Activity Contexts
-        if (getActivityToken() == null) {
-            throw new AndroidRuntimeException(
-                "Acquiring SearchManager objects only valid in Activity Contexts.");
-        }
         synchronized (mSync) {
             if (mSearchManager == null) {
                 mSearchManager = new SearchManager(getOuterContext(), mMainThread.getHandler());