Make the binder call in performHapticFeedback asynchronous.

Controlled by a build flag in ViewRootImpl.

This changes the return value to be true whenever it gets to dispatching
to binder - therefore it will no longer be false if the device has no
vibrator or if the HapticFeedbackConstant has no implementation. The
benefit is that the method should no longer have delays (including
binder scheduling ones) that can introduce jank on the UI thread.

The return code is currently undocumented and can be affected by a large
number of variables, so it seems unlikely to usefully deduce something
from it at runtime. In any case, the app would be better off, for
example, doing a one-off check separately, rather than a dynamic check
every time in this method that's asking to be called in the UI thread.

Bug: 264566815
Test: presubmit
Change-Id: I1c41ae26a1a9f0ad5a97b20d14a72d39ed8668ee