Adding IF NOT EXISTS to CREATE log_event_dropped (#3304)

* Adding IF NOT EXISTS to CREATE log_event_dropped

* DROP TABLE before CREATE log_event_dropped

Author: argzdev

transport/transport-runtime/src/main/java/com/google/android/datatransport/runtime/scheduling/persistence/SchemaManager.java

@@ -131,6 +131,7 @@ final class SchemaManager extends SQLiteOpenHelper {
 
   private static final SchemaManager.Migration MIGRATION_TO_V5 =
       db -> {
+        db.execSQL(DROP_LOG_EVENT_DROPPED_SQL);
         db.execSQL(CREATE_LOG_EVENT_DROPPED_TABLE);
         db.execSQL(CREATE_GLOBAL_LOG_EVENT_STATE_TABLE);
         db.execSQL(CREATE_INITIAL_GLOBAL_LOG_EVENT_STATE_VALUE_SQL);