Protect objects in Parcel::appendFrom

* only aquire objects within the range supplied to appendFrom
* don't append over existing objects
* unset the mObjectsSorted flag a couple more cases
* keep mObjectPositions sorted

Flag: EXEMPT bug fix
Ignore-AOSP-First: security fix
Test: binder_parcel_fuzzer
Bug: 402319736
Change-Id: I63715fdd81781aaf04f5fc0cb8bdb74c09d5d807