libaudiohal@aidl: Align position reporting with HIDL

Update comments in StreamHalInterface to align with HIDL HAL
framework contract. Update StreamHalAidl to match the contract.

Bug: 338557486
Test: atest CtsMediaAudioTestCases
(cherry picked from https://android-review.googlesource.com/q/commit:f0a9fbc32ce1a89d987e18580b28585c0b2f4bac)
Merged-In: I7c21b93c1cc985b7176d2e7ec0207ee0f9abbdb1
Change-Id: I7c21b93c1cc985b7176d2e7ec0207ee0f9abbdb1
4 files changed