Allow empty tokens in strict grammar

In SQLiteQueryBuilder, allow empty tokens when checking for invalid
tokens during the strict grammar check.

Fixes: 151151800
Fixes: 161769478
Test: atest SQLiteQueryBuilderTest#testStrictQueryEmptyToken
Change-Id: Iac1cdd643253fd186a164b863d65d6e92698fd38
(cherry picked from commit e409ec2492)

core/java/android/database/sqlite/SQLiteQueryBuilder.java

@@ -798,6 +798,7 @@ public class SQLiteQueryBuilder {
     }
 
     private void enforceStrictToken(@NonNull String token) {
+        if (TextUtils.isEmpty(token)) return;
         if (isTableOrColumn(token)) return;
         if (SQLiteTokenizer.isFunction(token)) return;
         if (SQLiteTokenizer.isType(token)) return;