NotificationHistory validate position value

We get a position value in a parcel and verify it is smaller than that
parcel's data size before setting it.

Flag: EXEMPT bug fix
Ignore-AOSP-First: security fix
Test: atest NotificationHistoryTest
Bug: 399155883
Change-Id: Ica98d82d7d7c1c9c0defcff8d96bf5f36e8f5d36