Aconfig: update cpp codegen

Update cpp codegen to read from both old and new storage for RW flags.
After comparison return old storage value and add a logcat log if the
value matches between the two storage pipeline. This codegen change is
not applied to nextfood build (as it is controlled by the build time
flag RELEASE_READ_FROM_NEW_STORAGE). In addition, the additional logic
to read from new storage is guarded by a RW aconfig flag.

Bug: b/321077378
Test: m and tested on a raven device
Flag: build.RELEASE_READ_FROM_NEW_STORAGE,
com.android.providers.settings.storage_test_mission_1
Ignore-AOSP-First: will fix any incompatibilities caused by this change in git main first, and then cherry pick it back to aosp

Change-Id: I9305bffa984ccae14543ffdce13974ab912e1c17