Fix full draw power usage increase issue

Full draw will be happened on HWUI under 144Hz device,there are
more draw commands under renderFrameImpl than in the 120Hz fps device,
frame.bufferAge() > (int)mSwapHistory.size() resulting in an increase
in power usage.

So need to increase (int)mSwapHistory.size() to 8.

Bug: 397592669
Test: Manual
1.Use the 144Hz device
2.Grab Settings Systrace of the sliding scene
3.Collect the Systrace, and check the drawing dirty area
is the screen area of the entire device

Change-Id: I477d37828f080e64cded9f285c58b7b27cbe6b03