Docs: Fixed an invalid initialization of ExampleProvider member in Content URI

public class ExampleProvider extends ContentProvider {

...

    // Creates a UriMatcher object.

    private static final UriMatcher sUriMatcher;

...

    private static final UriMatcher sUriMatcher = new UriMatcher(UriMatcher.NO_MATCH);

    static {

        /*

         * The calls to addURI() go here, for all of the content URI patterns that the provider

         * should recognize. For this snippet, only the calls for table 3 are shown.

         */

...

        /*

         * Sets the integer value for multiple rows in table 3 to 1. Notice that no wildcard is used

         * in the path

         * "content://com.example.app.provider/table3 doesn't.

         */

        sUriMatcher.addURI("com.example.app.provider", "table3/#", 2);

    }

...

    // Implements ContentProvider.query()

    public Cursor query(