Revert "ANDROID: fixup task_struct to avoid ABI breakage"

This reverts commit 4efa9734.

Bug: 439080322
Bug: 435308937
Signed-off-by: T.J. Mercier <tjmercier@google.com>
(cherry picked from https://android-review.googlesource.com/q/commit:4befbef4e6000d4ac04250e166c2e867990b3c17)
Merged-In: Ie1e6c164bb971735e2dc921c1d60626b263d68ae
Change-Id: Ie1e6c164bb971735e2dc921c1d60626b263d68ae