Fix use after move issue in AppOpsSession

In the ctor, we were accessing the already moved from  param in the
subsequent member initializers. Fix this.

There is also an issue with implicitly converting the return value.

Test: atest AppOpsSessionTests
Bug: 355498020
Flag: EXEMPT, safe adding utils
Change-Id: I5ab4b2ecdc72a049183af3be0344886ecc7db33a