Guard render metrics against too-large render times

Some apps may rely on SurfaceFlinger heuristics to change large invalid
desired render times to 'now' to render video frames as soon as
possible. Update render metrics to defensively handle these scenarios by
also assuming large invalid desired render times should actually be
'now'.

Bug: 294920725
Test: atest DecoderRenderTest#onFrameRendered_whenInvalidRenderTime_indicatesAllFramesRendered_vp9
Change-Id: If50ba1669ba0fdb3c0fbe5b322e12f8b421c9780