sepolicy[5/8]: allow installd to query ASEC size

installd need to query ASEC size on sdcard_external
to show on the Settings -> Apps page correctly.

Signed-off-by: Humberto Borba <humberos@gmail.com>
Change-Id: I2d9a49b8f0652f05d73d0ff464a3835595e2cc3c