Add current.txt HAL sections for S.

Adding these now, with a note that AIDL interfaces should be preserved,
to avoid some merge conflicts.

Bug: 147496715
Test: N/A
Change-Id: I67f6c5d583b853516c7203edb77f3c5fa841863b
(cherry picked from commit e6c11c94)
Merged-In: I67f6c5d583b853516c7203edb77f3c5fa841863b