aconfig: update storage unit test case

merge storage_test_1_part_1.aconfig and storage_test_1_part_2.aconfig
into one aconfig file: storage_test_1.aconfig

remove two flags from test_1 package so the total number of flags across
three aconfig package is now 8, which is easier to test in unit test.

Bug: b/312243587
Test: atest aconfig.test
Change-Id: Idd249a8dcddfbae09b211e6310d74697763618f4