message: Fix frame pacing on Android
  The renderer was misusing eglSetPresentationTime(), causing frame
  misses when a frame was completed quickly.
diff: @@ -266,8 +266,8 @@ void FRenderer::renderJob(ArenaScope& arena, FView& view) {
  recordHighWatermark(commands);
  }
  -void FRenderer::mirrorFrame(FSwapChain* dstSwapChain, Viewport const& dstViewport, Viewport const& srcViewport,
  - MirrorFrameFlag flags) {
  +void FRenderer::mirrorFrame(FSwapChain* dstSwapChain, Viewport const& dstViewport,
  + Viewport const& srcViewport, MirrorFrameFlag flags) {
  SYSTRACE_CALL();
  assert(mSwapChain);
  @@ -304,8 +304,7 @@ void FRenderer::mirrorFrame(FSwapChain* dstSwapChain, Viewport const& dstViewpor
  viewRenderTarget, dstViewport.left, dstViewport.bottom, dstViewport.width, dstViewport.height,
  viewRenderTarget, srcViewport.left, srcViewport.bottom, srcViewport.width, srcViewport.height);
  if (flags & SET_PRESENTATION_TIME) {
  - int64_t monotonic_clock_ns (std::chrono::steady_clock::now().time_since_epoch().count());
  - driver.setPresentationTime(monotonic_clock_ns);
  + // TODO: Implement this properly, see https://github.com/google/filament/issues/633
  }
  driver.endRenderPass();
  @@ -346,7 +345,6 @@ bool FRenderer::beginFrame(FSwapChain* swapChain) {
  int64_t monotonic_clock_ns (std::chrono::steady_clock::now().time_since_epoch().count());
  driver.beginFrame(monotonic_clock_ns, mFrameId);
  - driver.setPresentationTime(monotonic_clock_ns);
  if (!mFrameSkipper.beginFrame()) {
  mFrameInfoManager.cancelFrame();
  