Making the tests work on Android 2.3.1 (android-9)

Making the tests work on Android 2.3.1 (android-9)

Executing sql was failing:

```
org.wordpress.android.models.WordPressDB_NotificationsTest > testAddNoteClearNotes[test(AVD) - 2.2] FAILED 
	java.lang.IllegalArgumentException: You must supply an SQL string
	at android.database.sqlite.SQLiteDatabase.native_execSQL(Native Method)
```