aconfig: adjust integration tests to correctly set flag values

With the introduction of a root release config, the
com.android.aconfig.test flags now have their values correctly assigned.
Update the integration tests accordingly.

Bug: 317178122
Test: atest :all
Ignore-AOSP-First: submit internally first to resolve merge conflict from AOSP
Change-Id: I1acdf9442a465f20f71bcda9b15eb69058aa4b3a