Speculatively schedule input consumption

With the new tuned vsync offset, vsyncs are likely to occur shortly
after the input is received, meaning we will empty the input queue,
and thus won't schedule input consumption until more input is
received. If an application then speculatively posts draw commands to
the main looper faster than 60 hz, it will eventually end up blocking
in eglSwapBuffers. Since we're blocking in eglSwapBuffers, we won't
even schedule consumption until after the current frame (8-16ms), and
it's entirely likely we won't actually get around to consuming input
until after the next frame (another 16 ms of latency). This means we
can often go 16-32ms without processing any input events, causing
very noticeable amounts of jank.

Rather than waiting for the next input event to schedule input
consumption, speculatively schedule it every frame as long as we've
consumed some motion batch during this frame.

Bug: 11398045
Change-Id: I25e46308e00e9f9de00a1d8906f6b0e0f2e845b4