Revert "Death to synchronous transactions (2/2)"

This reverts commit dd05f036.

There seems to be some logic that gets triggered inside surface flinger
regarding commit time of the transaction, and without it seems that
animations got jankier. No time to investigate...

Bug: 28305789
Change-Id: I7261cf8719d3528f8f5bee19e507b8ba88b8b729